Cat Calorie Calculator

How do I use the cat calorie calculator?

1. Enter your cat’s weight in pounds or kilograms.
2. Choose the description that fits: neutered adult, intact adult, inactive, kitten, or needs to lose weight.
3. For weight loss, enter the ideal weight your vet gave you.
4. Read daily calories and the treat allowance. To turn calories into cans and cups, use the cat food calculator.

What is the formula for cat calories?

The resting energy formula and the neutered, intact, inactive and kitten factors come from the Merck Veterinary Manual. The 0.8 weight-loss starting point at ideal weight is common vet practice described in AAHA weight management guidance. It is a starting point your vet will adjust, not a fixed rule.

How is the calculation done?

For the default example, a 10 lb neutered adult cat:

1. Convert weight: 10 lb ÷ 2.2046 = 4.54 kg.
2. Raise to the 0.75 power: 4.54^0.75 = 3.108.
3. Multiply by 70: RER = 218 kcal.
4. Neutered adult: × 1.2 = 261 kcal a day. Range ±10%: 235–285 kcal.
5. Treat allowance: 10% = 26 kcal, about two or three small cat treats.

Worked example: a 12 lb cat that should weigh 10 lb

Your vet says your 12 lb cat’s ideal weight is 10 lb. Using the ideal weight and the 0.8 factor: RER at 10 lb is 218 kcal, times 0.8 = about 175 kcal a day. At a safe 0.5–2% a week, losing 2 lb will take a few months. That slow pace is on purpose: in cats, losing weight too fast can cause hepatic lipidosis, a dangerous liver disease.

How many calories does a cat need by weight?

Most healthy adult cats weigh roughly 8–11 lb, but frame size matters. Use body condition, not weight alone: you should feel the ribs under a light layer of fat and see a waist.

When should you see your vet?

• Before starting any weight-loss plan.
• If your cat stops eating for more than 24 hours, especially if overweight.
• If your cat loses weight while eating well; this can be a sign of thyroid disease or diabetes.
• If your cat has a health condition that needs a prescription diet.