Cat Calorie Calculator
Daily calories for your cat.
Starting estimate from published formulas. Your vet knows your pet.
How to use the cat calorie calculator
- Enter the cat's weight. The lb/kg switch converts it. It does not reset neuter status.
- Mark neutered or not. A neutered adult uses a lower factor than an intact adult.
- Mark obesity prone only when that describes the cat. Merck's row is 1 × resting energy, and the manual groups many indoor cats there.
- Leave weight-loss mode off for maintenance. Turn it on and type an ideal weight if the vet has one.
- Read kcal per day. Resting energy is beside it. The treat line is 10% of whichever headline is showing.
Three adult factors, and only one of them is the opening cat
Cat resting energy uses the same power as the dog: 70 × (kg)^0.75. The factor is where cats diverge. Merck lists intact adults at 1.4, neutered adults at 1.2, and obesity-prone adults at 1.0. Kittens are a separate 2.5 and are not on this page.
The page opens on a 10 lb neutered cat that is not marked obesity prone. Resting energy is 220 kcal. Maintenance is 260 kcal. The factor is 1.2 × RER. That is the 1.2 row, not the indoor row.
Marking obesity prone replaces 1.2 with 1.0 even if the cat is neutered. The control is a yes or no because Merck's table is a row, not a slider. If you are unsure, leave it off and ask the clinic. Guessing 'yes' underfeeds a cat that is merely quiet.
Weight loss uses a different power
AAHA's 2021 guidelines give a cat weight-loss mean of about 52 kcal times ideal kilograms to the power 0.711, with a spread of about 4.9 either side. The exponent is not 0.75. The weight is the ideal weight, not the weight on the scale this morning.
Mode off, the headline is maintenance: 260 kcal. The weight-loss mean for an ideal weight equal to today's weight is still listed as 150 kcal (low 140 kcal, high 165 kcal) so you can see it before you commit. Mode on, that mean becomes the headline and you must type the ideal weight.
Nothing here is a weekly loss target. 'How fast' is the vet's sentence. A cat that stops eating during a cut is an emergency, not a sign to wait for the next bowl.
Treats, indoor life, and the 30% gap
Treats under the headline are 25 kcal. Merck's feeding chapter puts treats under 10% of the day's calories so the rest of the diet can stay complete. A cat that lives on treats and a small dinner is not following that chapter.
Indoor life is not its own factor. If the cat is obesity prone, use that row. If the cat is a normal neutered adult who happens to live indoors, stay on 1.2 and watch the waist. The weight chart page is where body condition turns into an ideal weight.
Merck's caveat still applies: one cat may need 30% more or less than another of the same weight. The table below is the neutered, not-obesity-prone column plus the obesity-prone column, so you can see the gap without flipping the control for every weight.
Cat calories by weight
| Weight | Neutered maintenance | Obesity-prone | Weight-loss mean |
|---|---|---|---|
| 6 lb | 180 kcal | 150 kcal | 105 kcal |
| 8 lb | 220 kcal | 185 kcal | 130 kcal |
| 10 lb | 260 kcal | 220 kcal | 150 kcal |
| 14 lb | 335 kcal | 280 kcal | 195 kcal |
Weight-loss mean uses that weight as the ideal weight and AAHA's cat figure. Obesity-prone is Merck's 1 × resting energy row.
Tips and common mistakes
- Weigh the cat. A 'feels like 10 lb' guess is how the factor gets blamed for a wrong scale.
- Do not stack obesity-prone and weight-loss mode and then also remove treats you had already subtracted.
- The ideal-weight box appears only when weight-loss mode is on. Maintenance does not need it.
When to call your vet
- The cat has not eaten for a day, especially if you just cut the food. Cats that stop eating can become seriously ill quickly.
- Weight is falling and you did not plan a cut.
- You are feeding a kitten, a pregnant queen or a nursing queen. This page is the adult factor only.
- You want a number of grams to lose per week. That pace is not calculated here.
Frequently asked questions
How many calories does a 10 lb cat need?
The opening cat is 10 lb, neutered, not obesity prone. Maintenance is 260 kcal, from resting energy of 220 kcal times 1.2 × RER. Your cat moves off that number as soon as neuter status or the obesity-prone mark changes.
Do indoor cats need fewer?
Only if they belong on Merck's obesity-prone row, which is 1 × resting energy. Indoor by itself is not a factor. Leave the mark off unless that row really fits.
How fast should a cat lose weight?
This page does not answer in weeks or grams. It shows AAHA's intake range once you enter an ideal weight. The pace is agreed with the vet. A cat that refuses food during a diet needs a call the same day.
Where are the cans and cups?
On the cat food calculator. This page stops at calories so the factor stays visible. Cans need the kcal printed on your can, which is an input over there, not a guess here.
What about treats?
Keep them under 25 kcal, 10% of the headline. That limit is from Merck's feeding-practices chapter. It sits inside the day, not on top of a full bowl.