How many calories does my cat need per day?

Resting energy requirement (RER) is 70 × (weight in kg)^0.75. Maintenance needs for many neutered indoor cats are around 1.0–1.4× RER; outdoor and intact cats need more. Kittens, weight-loss plans and medical conditions need individual vet advice.

Can I use this to put my cat on a diet?

No. Rapid weight loss can cause hepatic lipidosis (fatty liver), which is life-threatening. This calculator is for maintenance estimates in healthy adult cats only. Ask your vet for a safe loss plan.

Do indoor cats need fewer calories?

Usually yes. Neutered indoor cats with little play often need the lower end of the range. Weigh food on kitchen scales and use body condition — you should feel ribs with light pressure.

Quick answer

The free PETHEALTH+ cat calorie calculator estimates a daily kcal range using RER (70 × kg^0.75) and lifestyle multipliers. It is a starting point only — confirm portions with your vet. Never crash-diet a cat; rapid loss risks fatty liver disease.

Cat calorie calculator

Estimate how many kilocalories (kcal) a healthy adult cat needs each day. This is a guide only — your vet should confirm portions, especially for kittens, nursing queens, seniors or weight-loss plans. Rapid dieting can cause fatty liver disease.

Based on WSAVA-style RER/MER formulas used in veterinary nutrition. Not a substitute for veterinary advice. See our cat obesity guide, food safety hub and the dog calorie calculator.

Frequently Asked Questions

How many calories does my cat need per day?: Resting energy requirement (RER) is 70 × (weight in kg)^0.75. Maintenance needs for many neutered indoor cats are around 1.0–1.4× RER; outdoor and intact cats need more. Kittens, weight-loss plans and medical conditions need individual vet advice.
Can I use this to put my cat on a diet?: No. Rapid weight loss can cause hepatic lipidosis (fatty liver), which is life-threatening. This calculator is for maintenance estimates in healthy adult cats only. Ask your vet for a safe loss plan.
Do indoor cats need fewer calories?: Usually yes. Neutered indoor cats with little play often need the lower end of the range. Weigh food on kitchen scales and use body condition — you should feel ribs with light pressure.