Cat Calorie Calculator
Daily calories your cat needs by weight, age and neuter status.
Reviewed by the Calculation Machine team · Updated 24 October 2026 · How we check our maths
Your values
ⓘ Live results
- Daily calories
- 260 kcal
- Resting requirement
- 216 kcal
- Dry food only
- 68 g per day
- Wet food only
- 324 g per day
- Half and half
- 34 g dry + 162 g wet
- Per meal (2 meals)
- 130 kcal
- Treat allowance (10%)
- 26 kcal
Working
- 1RER = 70 x 4.5^0.75 = 216 kcal
- 2216 x 1.2 = 260 kcal/day
Quick answer
A cat's daily calorie need starts from its resting energy requirement: RER = 70 × body weight in kg^0.75. Multiply RER by a life-stage factor, such as 1.2 for a neutered adult or 2.5 for a young kitten. A 4.5 kg neutered adult cat has an RER of about 216 kcal and needs about 260 kcal a day.
What the Cat Calorie calculator does
This calculator estimates how many kilocalories your cat needs each day, then converts that into grams of dry food, grams of wet food, or a half-and-half split, using the energy values printed on your cat food. It also shows the per-meal amount for two meals and a 10% treat allowance.
It uses the same resting energy equation and life-stage multipliers that vets use as a starting point. Every cat is different, though: two cats of the same weight can differ in needs by 20% or more because of activity, coat and metabolism. Feed the calculated amount for two to four weeks, weigh the cat, check its body condition, then adjust by about 10% at a time.
For weight loss, enter your cat's target weight rather than its current weight, and agree a plan with your vet. Cats that eat too little for even a few days can develop hepatic lipidosis (fatty liver), a serious illness. To see where your cat sits in its life, use the cat age calculator; for dogs, use the dog food calculator.
The formula
RER = 70 × W^0.75 Daily kcal = RER × factor Grams of food = daily kcal ÷ (kcal per 100 g) × 100
| Symbol | Meaning | Unit |
|---|---|---|
| W | Cat's body weight (target weight for weight loss) | kg |
| RER | Resting energy requirement: energy used at rest in a comfortable environment | kcal/day |
| factor | Life-stage multiplier from 0.8 (weight loss) to 2.5 (kitten under 4 months) | — |
| kcal per 100 g | Metabolizable energy from the food label, often listed as kcal/kg (divide by 10) | kcal/100 g |
The 70 × W^0.75 equation and life-stage factors are the standard approach in small-animal clinical nutrition, used in the WSAVA Global Nutrition Guidelines and veterinary nutrition textbooks. Factors are starting points, not exact values. The equation is less reliable for very small kittens and very obese cats, and cats with kidney, thyroid or diabetic conditions need a vet-set plan.
Worked examples
Overweight cat on a diet
A cat weighing 7.5 kg whose vet sets a target of 6.5 kg. Enter the target weight with the weight-loss factor, a 360 kcal/100 g dry food and an 85 kcal/100 g wet food.
Inputs
- Cat weight6.5 kg
- Life stageWeight loss
- Dry food energy360 kcal per 100 g
- Wet food energy85 kcal per 100 g
Result
- Daily calories228 kcal
- Resting requirement285 kcal
- Dry food only63 g per day
- Wet food only268 g per day
- Half and half32 g dry + 134 g wet
- Per meal (2 meals)114 kcal
About 228 kcal a day, which is 63 g of the dry food or 268 g of the wet. Weigh the cat every two weeks; aim for a slow, steady loss and talk to your vet if it stalls or speeds up.
Growing kitten
A 6-month-old kitten weighing 2 kg, fed a kitten dry food at 410 kcal/100 g and a kitten wet food at 95 kcal/100 g.
Inputs
- Cat weight2 kg
- Life stageKitten 4-12 months
- Dry food energy410 kcal per 100 g
- Wet food energy95 kcal per 100 g
Result
- Daily calories235 kcal
- Resting requirement118 kcal
- Dry food only57 g per day
- Wet food only248 g per day
- Half and half29 g dry + 124 g wet
- Per meal (2 meals)118 kcal
Around 235 kcal a day, nearly as much as a 4.5 kg adult. Kittens need several small meals, and the amount should be recalculated every few weeks as they grow.
Quiet senior cat
A 4 kg 13-year-old cat that sleeps most of the day.
Inputs
- Cat weight4 kg
- Life stageSenior, low activity
- Dry food energy380 kcal per 100 g
- Wet food energy80 kcal per 100 g
Result
- Daily calories218 kcal
- Resting requirement198 kcal
- Dry food only57 g per day
- Wet food only272 g per day
- Half and half29 g dry + 136 g wet
- Per meal (2 meals)109 kcal
About 218 kcal, or a mix of 29 g dry and 136 g wet. Some older cats lose weight as digestion becomes less efficient, so if weight falls on this amount, increase it and mention it to your vet.
Life-stage factors and when to use each
Pick the line that best matches your cat. If you are unsure between two, start with the lower factor and adjust after weighing.
| Life stage | Factor | Use when |
|---|---|---|
| Kitten under 4 months | 2.5 | Fast growth; feed several small meals |
| Kitten 4–12 months | 2.0 | Growth slowing toward adult size |
| Neutered adult | 1.2 | Most pet cats aged 1–10 |
| Intact adult | 1.4 | Not neutered or spayed |
| Senior, low activity | 1.1 | Older, mostly resting cats at a healthy weight |
| Weight gain | 1.6 | Underweight cats, under veterinary guidance |
| Weight loss | 0.8 | Enter target weight, not current weight |
Reading the food label
Calorie content is usually printed near the feeding guide as "metabolizable energy" in kcal/kg, sometimes also per can or pouch. Divide kcal/kg by 10 to get kcal per 100 g. Typical values:
- Dry food: about 350–420 kcal per 100 g.
- Wet food: about 70–110 kcal per 100 g, because it is around three-quarters water.
The pack's feeding guide is often generous because it covers active, unneutered cats. Weighing dry food on a kitchen scale is far more accurate than using a cup, since a cup of kibble can vary by 20% or more depending on how it is filled.
Checking the result with body condition
Calories are an estimate; your cat's shape is the test. On a healthy cat you can feel the ribs under a light layer of fat without pressing hard, see a waist behind the ribs from above, and see only a small belly pouch. If ribs are hard to feel, reduce the daily amount by about 10%; if they are sharp to the touch or the hips stick out, increase it and check with your vet. Treats, dental chews and milk all count toward the daily total, which is why the calculator caps them at 10%.
How to use the Cat Calorie Calculator
- 1Weigh your cat on a pet scale, or weigh yourself holding the cat and subtract your own weight.
- 2Choose the life stage; for weight loss, enter the target weight your vet suggests instead of the current weight.
- 3Enter the kcal per 100 g for your dry and wet foods from the labels (kcal/kg ÷ 10).
- 4Use the grams per day for one food or the half-and-half split, divided across meals, and reweigh in 2–4 weeks.
Frequently asked questions
How many calories should a cat eat a day?
A typical 4–5 kg neutered indoor adult needs roughly 240–280 kcal a day. Kittens, intact cats and very active cats need more; seniors and cats on a diet need less.
How much wet food should I feed my cat?
Divide daily calories by the wet food's kcal per 100 g and multiply by 100. For a 260 kcal cat on an 80 kcal/100 g food, that is about 325 g a day, roughly four 85 g pouches.
How fast should an overweight cat lose weight?
Slowly, at around 0.5–1% of body weight per week. Losing weight too fast or going without food can trigger hepatic lipidosis, so diets should be planned with a vet. The weight loss percentage calculator shows what share of body weight has been lost between weigh-ins.
Why is my cat always hungry?
Dry food is calorie-dense and small in volume, so a correct ration can look meager. Moving part of the ration to wet food gives a bigger meal for the same calories; sudden increases in appetite with weight loss need a vet check.
Should I feed my cat by the bag or by calories?
Use the bag as a rough guide and calories for accuracy. Calculating from your cat's weight and life stage is more precise, especially for neutered or indoor cats that need less than the bag suggests.
References
- WSAVA Global Nutrition Guidelines — World Small Animal Veterinary Association
- Small Animal Clinical Nutrition (5th edition) — Mark Morris Institute
- Nutrient Requirements of Dogs and Cats (2006) — National Research Council, National Academies Press
About this calculator
- Built and reviewed by the Calculation Machine team · How we build and test calculators
- Last reviewed: October 24, 2026
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