Cat Calorie Calculator
Enter your cat's weight and life stage to estimate daily calorie needs using a standard veterinary energy formula. This is an educational starting point, not a prescribed feeding plan.
Last updated: September 22, 2026
Frequently asked questions
What is RER and why does the formula use weight to the power of 0.75?
RER (resting energy requirement) is the energy a cat needs at complete rest to maintain basic body functions. The exponent 0.75 reflects that metabolic rate doesn't scale directly with body mass - smaller animals burn more calories per unit of body weight than larger ones, and this allometric scaling formula (70 × weight in kg^0.75) is the standard veterinary approach across cat and dog sizes.
What does the life stage multiplier actually represent?
It scales RER up to maintenance energy requirement (MER) based on how much energy a cat typically uses beyond resting metabolism for that life stage - a growing kitten needs several times its resting energy for tissue development, while a neutered, less active adult needs comparatively less than an intact, more active one. These are commonly cited veterinary starting multipliers, not exact values for every individual cat.
Why is the neutered/spayed multiplier lower than the intact multiplier?
Neutering and spaying are associated with a measurable drop in metabolic rate and activity in many cats, so veterinary references commonly recommend a lower maintenance multiplier for neutered cats to avoid gradual overfeeding - though individual metabolism still varies, and body condition should guide actual portions over time.
Should I use this number to put my cat on a diet?
This calculator gives an educational starting estimate, not a restrictive feeding plan - weight management in cats should be supervised by a veterinarian, since overly rapid weight loss in cats carries real health risks (including hepatic lipidosis). If weight is a concern, use this figure as a conversation starter with your vet rather than a number to enforce on your own.
Why is the pregnant/nursing multiplier so much less precise than the others?
Energy needs during pregnancy and especially peak lactation can rise dramatically and unpredictably - lactating queens can need several times their normal maintenance energy depending on litter size and stage of nursing. This tool shows a conservative starting multiplier, but pregnant or nursing cats should be monitored and fed under veterinary guidance rather than by a fixed formula.
How is this different from the general Calorie Calculator on this site?
The general Calorie Calculator uses human metabolic formulas (based on human age, sex, height, and activity) and isn't applicable to cats. This calculator uses the feline RER/MER framework instead, which is scaled and validated for cats rather than adapted from human equations.