Cat Age Calculator & More

Cat Age Calculator — Convert Cat Years to Human Years Accurately

CatCalc.online is a free, science-based toolkit for cat owners who want clear answers about age, nutrition, weight, and breeding. The classic “multiply by seven” rule is outdated and often misleading. Cats mature extremely quickly in their first two years, then age more steadily. Modern veterinary guidance from the American Veterinary Medical Association (AVMA) and the American Association of Feline Practitioners (AAFP) gives a much more realistic picture of how old your cat is in human terms—and when they move from kitten to adult, mature, senior, or geriatric stages.

Our cat age calculator and the companion tools on this site use those veterinary standards so you can plan care, feeding, and check-ups with more confidence. Everything runs in your browser: no account, no data stored on our servers, and no cost.

How Cat Years Convert to Human Years

According to widely used AVMA and AAFP life-stage guidelines:

• Year 1 of a cat’s life ≈ 15 human years (kittenhood through early adolescence).
• Year 2 adds about 9 human years, so a 2-year-old cat is roughly equivalent to a 24-year-old human.
• Each year after age 2 adds approximately 4 human years.

So a 5-year-old cat is about 36 in human years, a 10-year-old about 56, and a 15-year-old about 76. Unlike dogs, cats of different sizes tend to age at a more similar rate; breed and size still matter for expected lifespan and health risks, but the core conversion is the same for most household cats.

Cat age to human years chart (quick reference)

These numbers are educational estimates. Individual cats vary with genetics, indoor vs outdoor lifestyle, diet, dental health, and medical history. Always use the results together with your veterinarian’s advice.

Feline Life Stages Explained

Understanding life stage helps you choose the right food, exercise, and veterinary schedule:

• Kitten (birth to 1 year) — Rapid growth, high calorie needs, vaccination and socialization period.
• Junior / young adult (1–2 years) — Near adult size; energy remains high; sterilisation is often considered.
• Adult (3–6 years) — Maintenance phase; focus on weight control and dental care.
• Mature (7–10 years) — Early signs of aging may appear; twice-yearly check-ups become more valuable.
• Senior (11–14 years) — Higher risk of kidney, thyroid, and joint issues; diet and monitoring often change.
• Geriatric / super senior (15+ years) — Comfort, mobility, and quality of life are priorities; frequent veterinary contact is recommended.

Our Cat Life Stage Calculator classifies your cat using these ranges so you can see at a glance where they sit and what care themes usually apply.

All Calculators on CatCalc.online

Beyond age conversion, the site includes feeding, weight, and breeding tools that follow the same private, browser-based approach.

1. Cat Age Calculator — Birth Date to Human Age

Enter your cat’s date of birth (and optionally breed/size). The tool returns exact age in years and months, the human-year equivalent using the 15 / 9 / 4 method, and the current life stage. Ideal when you know the birthday and want a complete snapshot.

2. Cat Years to Human Years Calculator

Enter age in years and months if you do not have an exact birth date. Results show the AVMA-style human equivalent and life stage. Useful for rescue cats or when only an approximate age is known.

3. Human Years to Cat Years Calculator

Reverse conversion: pick a human age and see the approximate corresponding cat age. Helpful for comparing milestones or explaining age to family members.

4. Cat Birthday Calculator

Shows current age, human-year equivalent, and the next birthday with days remaining—handy for celebrations and annual reminder planning.

5. Cat Life Stage Calculator

Dedicated life-stage output (kitten through geriatric) based on age. Supports decisions about diet type, check-up frequency, and senior care.

6. Cat Age in Months Calculator

Especially useful for kittens. Enter age in months only and get human-year equivalent plus life stage without converting months to years yourself.

7. Cat Calorie Calculator

Estimates daily energy needs using the standard veterinary formula:

RER (Resting Energy Requirement) = 70 × (body weight in kg)^0.75

Then multiplies by a life-stage and activity factor to produce MER (Maintenance Energy Requirement). Factors cover kittens, intact and neutered adults, seniors, and more active cats. Results are a starting point; adjust with your vet based on body condition and trends on the scale.

8. Cat Weight Loss Calorie Calculator

Suggests a lower daily calorie target for gradual weight loss, ideally calculated from an estimated ideal weight rather than current overweight weight. Aim for slow loss (often around 0.5–2% of body weight per week under veterinary guidance) to protect muscle and organ health.

9. Cat Water Intake Calculator

Estimates daily water needs in millilitres (and cups/ounces) from weight and activity. Cats often drink less than they should, especially on dry food. Wet food, fountains, and multiple water stations help; this calculator gives a baseline range so you can notice under-drinking early.

10. Cat Ideal Weight & Body Condition Score Calculator

Uses the common 1–9 Body Condition Score (BCS). Score 4–5 is generally ideal. From current weight and BCS, the tool estimates an ideal weight range. Pair the number with a hands-on check (ribs easy to feel with a slight fat cover, visible waist from above, abdominal tuck from the side).

11. Kitten Adult Weight Predictor

Gives a rough projection of adult weight from current kitten weight and age in months. Growth curves vary widely by breed and sex; treat the result as a rough guide and confirm with breed standards and your veterinarian.

12. Cat BMI & Body Condition Guidance

True BMI (weight ÷ height²) is not validated across cat breeds the way it is in humans. We explain why BCS is preferred and point you to the ideal-weight tool for practical use.

13. Cat Pregnancy Calculator & Due Date

Cat gestation averages about 63–65 days from ovulation (often roughly 58–70 days from mating, depending on timing). Enter mating, ovulation, or related date type to get an estimated due window. Ultrasound confirmation and veterinary care remain essential.

14. Cat Gestation & Kitten Due Date

Same core timing logic with clear windows so you can prepare a queening area and know when to contact the clinic if labour is delayed or complicated.

15. Cat Heat Cycle Calculator

Estimates the next heat from the start of the previous cycle. Interval length varies a lot (often several weeks to months, and seasonally in some climates). Tracking individual patterns is more reliable than a single average.

16. Kitten Birth Weight Guidance

Newborn weight varies by litter size and breed. Low birth weight or failure to gain in the first days needs prompt veterinary attention. Daily weighing in the early weeks is one of the best home monitoring habits.

How to Use the Calculators

1. Open the category tab you need: Age, Feeding, Weight & Growth, or Breeding.
2. Enter the requested values (date of birth, age in years/months, weight, BCS, mating date, etc.).
3. Select breed or size when offered—this improves context for life stage and expectations even when the core age formula is the same across cats.
4. Tap the calculate button. Results appear instantly below the form.
5. Use the numbers as a guide, then discuss diet, weight targets, or pregnancy plans with your veterinarian.

All math runs locally in your browser. We do not require sign-up and do not store the ages, weights, or dates you enter.

Key Features of CatCalc.online

• Veterinary-aligned formulas — Age uses AVMA/AAFP-style 15 / 9 / 4 logic; calories use RER = 70 × kg^0.75.
• 100+ cat breeds — From Domestic Shorthair and Siamese to Maine Coon, Ragdoll, Bengal, Sphynx, British Shorthair, and many more, with simple size tags where helpful.
• Full life-stage coverage — Kitten through geriatric, not only a single “senior” label.
• Feeding and weight tools in one place — Calories, weight-loss targets, water, and BCS-based ideal weight.
• Breeding timeline support — Pregnancy due windows and heat-cycle estimates for responsible planning.
• Private by design — Calculations stay on your device.
• Mobile-friendly — Works on phones and tablets for quick checks at home or at the clinic waiting room.
• Multi-language — English plus Arabic, French, Spanish, German, Norwegian, Japanese, Korean, and Dutch, with automatic language detection and a manual switcher.
• Free — No subscriptions or paywalls for the core calculators.

Why Accurate Cat Age Matters

Age affects almost every care decision: vaccine boosters, parasite control, dental exams, bloodwork frequency, calorie targets, and when to switch to senior diets. A cat that is “about 8” is already in the mature-to-senior transition in human terms (around 48). Knowing that helps you act earlier on weight, thirst, litter-box changes, or mobility—often before problems become emergencies.

For kittens, month-by-month age drives deworming, vaccination schedules, and growth monitoring. For seniors, it supports proactive screening for chronic kidney disease, hyperthyroidism, arthritis, and dental disease—the conditions that most often shape quality of life in older cats.

Feeding, Calories, and Healthy Weight

Obesity is common in indoor cats and is linked to diabetes, joint stress, and shorter lifespan. Underweight cats may hide dental pain, hyperthyroidism, or other illness. The calorie and ideal-weight calculators give structure to conversations with your vet:

• Start from RER, then apply the right factor for life stage and neuter status.
• For weight loss, calculate from an estimated ideal weight, not only current weight, and aim for gradual change.
• Recheck body condition every few weeks; numbers on the bag are averages, not prescriptions.

Water intake is easy to overlook. Cats have a low thirst drive compared with dogs. If your cat eats mainly dry food, the water calculator’s range is a useful benchmark; increased drinking can also be an early sign of disease and should be mentioned at the clinic.

Pregnancy and Heat Cycles

If you are breeding or caring for an intact queen, timing matters. Average gestation is about nine weeks, but the useful planning window is wider when you only know the mating date. Our pregnancy tools give earliest, average, and latest style guidance so you can prepare a quiet queening space and know when to seek help. Heat intervals are highly individual; the heat-cycle calculator is a planning aid, not a guarantee—record your own cat’s pattern for the best predictions.

Frequently Asked Questions

How do I convert cat years to human years?

Use the 15 / 9 / 4 method: first year ≈ 15 human years, second year brings the total to about 24, then add 4 human years for each additional cat year. Enter age (or birth date) in our Cat Years to Human Years calculator for an instant result and life stage.

Is the “one cat year = seven human years” rule correct?

No. It underestimates early maturation and does not match how cats develop. A 1-year-old cat is closer to a mid-teen human than to a 7-year-old child.

At what age is a cat considered senior?

Many guidelines treat cats as senior from about 10–11 years of age (roughly mid-50s in human terms), with mature years starting around 7. Individual health matters more than the birthday alone.

Do different breeds age at different speeds?

Cats are more uniform than dogs in year-to-year conversion, but large breeds such as Maine Coons may take longer to reach full adult size, and some breeds have different average lifespans. Use breed context for expectations; use the standard conversion for day-to-day human-year estimates.

How many calories does my cat need per day?

It depends on weight, whether they are neutered, activity, and life stage. Calculate RER with 70 × (kg)^0.75, then multiply by an appropriate factor (often around 1.2 for many neutered indoor adults, higher for kittens and intact or very active cats). Our Cat Calorie Calculator does this automatically; your vet may refine the target after examining body condition.

How much water should a cat drink?

A common baseline is on the order of 40–60+ ml per kg body weight per day, depending on diet moisture, temperature, and activity. Wet food contributes significant water. Sudden increases in thirst warrant a veterinary check.

How long is a cat pregnant?

Typically about 63–65 days from ovulation. Counting from mating can span a wider window because ovulation timing varies. Confirm pregnancy and timing with your veterinarian (often via ultrasound).

Are these calculators a substitute for veterinary care?

No. They are educational tools for orientation and planning. Diagnosis, treatment, diet prescription, and breeding decisions should involve a licensed veterinarian who knows your cat.

Is my data private?

Yes. Calculations run in your browser. We do not need an account and do not store the values you type into the forms.

Can I use the tools on my phone?

Yes. The site is responsive and works on modern mobile browsers as well as desktop.

Tips for Getting the Most Accurate Results

• Weigh your cat on a reliable scale (baby scale or by weighing yourself holding the cat, then subtracting).
• For age tools, use the best known birth date or a vet’s age estimate for rescues.
• Score body condition honestly—many owners underestimate overweight.
• Recalculate after weight change, sterilisation, or a move from kitten to adult food.
• Keep a simple log of weight, appetite, water, and litter-box habits; trends matter as much as single numbers.

About CatCalc.online

CatCalc.online brings cat age conversion, nutrition estimates, weight guidance, and breeding timelines into one free, ad-light experience. The goal is practical clarity: know roughly how old your cat is in human years, what life stage they are in, how many calories and how much water are reasonable starting points, and when a due date or heat might fall—then partner with your veterinarian for personalised care.

Whether you share your home with a lively kitten, a laid-back adult Domestic Shorthair, a majestic Maine Coon, or a distinguished senior, the calculators are here to support informed, kind decisions throughout their life.

Disclaimer: All results are approximate educational estimates based on published veterinary guidelines and typical values. They are not medical advice. Always consult a qualified veterinarian about your cat’s health, diet, and reproductive care.

CatCalc.online — Complete Guide to Every Calculator

CatCalc.online is built so you never have to guess about your cat’s age, food, weight, or breeding timeline. Below you will find a full walkthrough of every category and every calculator: what it does, when to use it, how to read the result, and how it fits into real-world cat care. All tools are free, run in your browser, and keep your inputs private.

Category 1: Age Calculators

Age is the foundation of feline care. It drives vaccination timing, diet type, dental checks, bloodwork frequency, and when you start thinking about senior support. Cats do not age like the old “×7” myth suggests. They race through childhood in the first year, reach a young-adult human equivalent by year two, then add roughly four human years for each further cat year. This category turns that science into clear numbers and life-stage labels.

Cat Age Calculator — Birth Date to Human Age

This is the most precise age tool when you know your cat’s birthday. Enter the date of birth and, if you like, a breed or size. The calculator returns:

• Exact age in years and months (and total months)
• Human-equivalent age using the AVMA-style method (year 1 ≈ 15, year 2 ≈ 24 total, then +4 per year)
• Current life stage (kitten, junior, adult, mature, senior, or geriatric)

How to use it: Pick the birth date from the calendar, choose the closest breed or size from the list, and tap calculate. If you adopted a cat and only have an approximate birthday from the shelter or vet, use the best date you have—results will still orient you better than a rough guess.

Why it matters: A “3-year-old” cat is already about 28 in human terms—prime adult. A “12-year-old” is around 64 and firmly senior. Knowing both the calendar age and the human equivalent helps you and your family treat life-stage needs seriously without waiting for obvious illness.

Cat Years to Human Years Calculator

Use this when you know age in years (and maybe months) but not the exact birth date. Enter years, optional extra months, and breed/size. You get the same human-year estimate and life-stage badge as the birth-date tool.

How to use it: Type whole years (for example 7) and months if needed (for example 3). Select breed or size. Calculate. Ideal for rescue cats, strays with vet-estimated ages, or quick checks when you only remember “about eight.”

Tip: If the vet estimated “between 4 and 6,” run the calculator at both ends of the range so you understand the possible human-year and life-stage span.

Human Years to Cat Years Calculator

This reverses the conversion. Enter a human age and a size category; the tool estimates the matching cat age. It is useful for explaining milestones (“a 40-year-old human is roughly like a 6-year-old cat”) or comparing life stages across species in educational content.

How to use it: Enter the human age in years, pick breed/size, calculate. Remember this is an approximation of the same 15 / 9 / 4 curve run backwards—not a medical diagnosis of your cat’s biological age.

Cat Birthday Calculator

Beyond “how old,” this tool answers “when is the next birthday?” Enter birth date and optional breed/size. You receive current age, human-year equivalent, the next birthday date, and days remaining.

How to use it: Same birth-date input as the main age calculator. Use it for annual reminders, adoption-day alternatives when the real birthday is unknown, or simply to celebrate your cat on the right day.

Care angle: Birthdays are a natural cue to book the annual (or twice-yearly senior) exam, update weight logs, and review diet.

Cat Life Stage Calculator

Dedicated to classification only. Enter age in years and months plus size; the result highlights whether your cat is a kitten, junior/young adult, adult, mature, senior, or geriatric/super senior, with the matching human-year context.

Typical ranges used on CatCalc:

• Kitten: under 1 year
• Junior / young adult: 1 to under 2 years
• Adult: 2 to under 7 years
• Mature: 7 to under 11 years
• Senior: 11 to under 15 years
• Geriatric / super senior: 15 years and older

How to use it: When you only care about the stage label for food choice, check-up frequency, or product labels that say “senior,” this calculator is the fastest path.

Cat Age in Months Calculator

Built for kittens and precise early growth tracking. Enter age purely in months (for example 14 or 20). The tool converts to years, human equivalent, and life stage without you doing the division yourself.

How to use it: Essential during the first year when vaccine and deworming schedules are month-based. Also useful for adolescents still measured in months by the clinic.

Age category summary

Together these six tools cover every common situation: known birthday, approximate age, reverse conversion, next celebration, stage-only answers, and month-based kitten math. They all share the same veterinary-style aging curve so results stay consistent when you move from one tool to another.

Category 2: Feeding Calculators

Food is the daily lever you control most. Too many calories and indoor cats gain weight quickly; too few and kittens or recovering cats lose condition. This category estimates energy needs and water, always as a starting point to refine with body condition and veterinary advice.

Cat Calorie Calculator

Estimates how many kilocalories (kcal) your cat needs per day. The engine uses the standard veterinary Resting Energy Requirement:

RER = 70 × (body weight in kilograms)^0.75

That baseline is then multiplied by a life-stage / activity factor to produce Maintenance Energy Requirement (MER)—the practical daily target for many healthy cats.

Typical factors you can select:

• Kitten (higher multipliers while growing)
• Intact adult
• Neutered adult (often lower than intact)
• Senior or lower activity
• More active or working-style needs when relevant

How to use it: Enter current weight, choose kg or lb, pick the factor that best matches your cat, calculate. You will see RER and the adjusted daily kcal. Compare that to the kcal per 100 g (or per can/cup) on your food label to estimate portion size—then adjust if the waistline changes.

Important: Labels and calculators are averages. Neutered indoor cats often need less than package “feeding guides.” Re-weigh every 2–4 weeks when changing amounts.

Cat Weight Loss Calorie Calculator

Obesity is one of the most common preventable problems in house cats. This tool suggests a lower daily calorie target aimed at gradual loss. It works best when you also estimate ideal weight (see the weight category). Feeding for weight loss is often planned from ideal-weight energy needs, not from the higher current weight, to avoid cutting food too aggressively.

How to use it: Enter current weight and optional ideal/target weight, choose units, calculate. Use the suggested kcal only under veterinary supervision if your cat has medical issues, is very overweight, or is a kitten. Target slow loss—commonly on the order of about 0.5–2% of body weight per week depending on the case—so muscle and organs stay protected.

Pair with: Body Condition Score, regular weighing, and puzzle feeders or play to increase activity without stressing joints.

Cat Water Intake Calculator

Cats evolved as efficient desert hunters and often drink less than owners expect. Low water intake plus dry food can contribute to concentrated urine and urinary problems. This calculator estimates a daily water range from weight and activity level (ml, cups, and fluid ounces).

How to use it: Enter weight, unit, and activity (low / moderate / high). Treat the result as a baseline. Wet food already supplies moisture; cats on dry-only diets usually need more water from bowls or fountains. Sudden large increases in drinking can signal disease (for example kidney or thyroid issues) and should be checked by a vet.

Practical tips: Multiple water stations, wide bowls, running-water fountains, and a little water mixed into wet food all encourage intake.

Feeding category summary

Use calories for everyday portions, weight-loss calories when the BCS is high, and water intake to judge hydration habits. None of these replace a diet designed by your veterinarian for kidney disease, diabetes, or other conditions—but they stop pure guesswork for healthy cats.

Category 3: Weight & Growth Calculators

The scale and your hands (ribs, waist, belly tuck) tell the truth about condition. This category turns weight and Body Condition Score into ideal-weight estimates and rough adult projections for kittens.

Cat Ideal Weight & Body Condition Score Calculator

Veterinarians use a 1–9 Body Condition Score (BCS). Around 4–5 is ideal for most cats: ribs easy to feel under a thin fat layer, waist visible from above, slight belly tuck from the side. Scores 1–3 are too thin; 6–7 overweight; 8–9 obese.

This calculator takes current weight and BCS and estimates an ideal weight by adjusting roughly 10% per score point away from ideal. It is a structured estimate, not a lab measurement.

How to use it: Weigh the cat, score BCS as honestly as you can (photos from above and the side help), enter both, calculate. Use the ideal weight as a goalpost for the weight-loss calorie tool and for progress checks.

Why not human-style BMI? Cats vary enormously in leg length, chest shape, and coat. Weight divided by height squared has not been validated the way BCS has in clinical practice—so we guide you toward BCS first.

Kitten Adult Weight Predictor

Growing kittens make owners wonder “how big will they get?” This tool projects a rough adult weight from current weight and age in months. Real growth is not perfectly linear and differs by breed, sex, and nutrition, so the number is illustrative.

How to use it: Enter current weight, age in months, and unit. Compare the projection with breed standards (Maine Coons finish larger and later than Singapuras, for example). Recheck every month; the curve will settle as the kitten approaches adulthood.

Caution: Underweight or overweight kittens need veterinary input before any “diet” ideas. Growth and development come first.

Cat BMI & Body Condition Guidance

This section explains why BCS beats BMI for cats and points you back to the ideal-weight calculator. It exists so searchers looking for “cat BMI” still find accurate guidance instead of a misleading human formula.

Weight category summary

Weigh regularly, score condition with your hands, estimate ideal weight, and only then set calorie targets. For kittens, track weight gain and use the predictor as a curiosity tool—not as a strict destiny.

Category 4: Breeding & Reproduction Calculators

Whether you are an intentional breeder or managing an intact queen, timing reduces stress and improves safety. These tools estimate due windows and heat timing. They do not replace ultrasound, progesterone testing, or emergency veterinary access.

Cat Pregnancy Calculator & Due Date

Domestic cat pregnancy (gestation) typically lasts about 63–65 days from ovulation. When you only know the mating date, the realistic window is wider—often discussed around the high 50s to about 70 days—because ovulation may not line up with the day of mating.

How to use it: Enter the relevant date and choose whether it represents mating, ovulation, or another supported type if offered. The result shows an average due date and a practical early–late window so you can prepare a quiet queening area, gather supplies, and know when to call the clinic if labour is late or difficult.

Care notes: Confirm pregnancy with your veterinarian. Monitor appetite, weight, and behaviour in late pregnancy. Know the location of 24-hour care before the due window starts.

Cat Gestation & Kitten Due Date Calculator

Reinforces the same gestation logic with clear educational copy about stages of pregnancy and why windows matter more than a single magic day. Use it alongside the pregnancy calculator when you want due-date planning spelled out in plain language.

Cat Heat Cycle Calculator

Queens can cycle repeatedly during breeding seasons. Interval length varies widely by individual, daylight, and climate. This calculator estimates the next heat from the start date of the previous cycle and an optional typical cycle length in days.

How to use it: Enter the first day of the last heat and your best guess at cycle length (or leave a default average). The tool projects a next heat date. Treat it as a planning aid; keep your own calendar for higher accuracy over time.

Context: Spaying prevents heat cycles and unplanned litters. If you are not breeding, discuss sterilisation timing with your vet.

Kitten Birth Weight Guidance

Newborn kitten weights vary with litter size, breed, and prenatal nutrition. Very small kittens or those that fail to gain weight in the first 24–72 hours need urgent help. This module explains why daily weighing matters and what “normal variation” means—without pretending one number fits every breed.

How to use it: Read the guidance, then weigh kittens daily on a precise scale and record results. Contact a veterinarian immediately if a kitten is limp, cold, not nursing, or losing weight.

Breeding category summary

Due-date and heat tools support preparation and record-keeping. Health screening, genetic responsibility, neonatal care, and veterinary partnership remain the core of ethical breeding—not the calculator alone.

How the Four Categories Work Together

A typical care path looks like this:

1. Age tools — Establish calendar age, human equivalent, and life stage.
2. Weight tools — Weigh, score BCS, estimate ideal weight.
3. Feeding tools — Set calorie and water baselines; tighten calories if weight loss is needed.
4. Breeding tools — Only when relevant; otherwise skip.

Revisit age stage after each birthday, weight and calories whenever the body changes shape, and water anytime drinking habits shift.

Features That Apply to Every Calculator

• Instant results — No waiting, no email gate.
• Breed list — 100+ breeds and mixed-breed size options for context.
• Unit flexibility — kg/lb where weight is required.
• Privacy — Inputs stay in your browser.
• Mobile layout — Usable on phone screens.
• Consistent formulas — Age and energy math align with common veterinary teaching values.
• Clear disclaimers — Educational estimates, not a diagnosis.

Step-by-Step: First-Time Users

1. Open CatCalc.online on any device.
2. Choose a tab: Age, Feeding, Weight & Growth, or Breeding.
3. Fill only the fields you know; optional fields can wait.
4. Press the calculate button and read the result box.
5. Save or screenshot numbers if you want to show your vet.
6. Adjust food or book an appointment based on professional advice—not on the calculator alone.

Cat Age Chart (Reference)

Frequently Asked Questions

What formula does the cat age calculator use?

Year 1 ≈ 15 human years, year 2 ≈ 24 total, then about +4 human years for each additional cat year—aligned with common AVMA/AAFP-style teaching charts.

Which calculator should I use for a rescue cat with unknown birthday?

Use Cat Years to Human Years or Life Stage with the vet’s age estimate. If they give a range, run both ends.

How do I pick the right calorie factor?

Neutered indoor adults often sit near the lower adult factors; kittens need higher multipliers; seniors may need adjustment for activity and disease. When in doubt, start conservatively and let weight trends guide changes with your vet.

Can the weight-loss calculator be used for kittens?

No. Growing kittens should not be put on adult weight-loss plans without specialist advice. Use age and calorie tools meant for growth instead.

How accurate is the pregnancy due date?

Average gestation is about 63–65 days from ovulation, but mating-only dates produce wider windows. Ultrasound and clinical care refine timing.

Why is my cat always hungry on the calculated calories?

Food composition, treat habits, boredom, medical issues (for example hyperthyroidism in older cats), and under-estimated activity all play roles. Rule out medical causes and measure food precisely before increasing portions.

Do you store my cat’s data?

No. Calculations are performed locally in your browser.

Are the tools free on mobile and desktop?

Yes. The full set is free to use on modern browsers without installing an app.

Final Notes

CatCalc.online exists to make veterinary-style estimates usable at home: age and life stage, calories and water, ideal weight and kitten growth, pregnancy and heat timing. Use every calculator as a compass, then let a veterinarian who knows your cat set the destination—especially for illness, rapid weight change, breeding decisions, or senior care.

Explore each tab, run the tools that match your situation, and return after the next weigh-in or birthday. Clear numbers make kinder care easier.

Educational use only. Not a substitute for professional veterinary diagnosis, nutrition prescription, or reproductive care.