Calorie Cats Calculator
Cat Calorie Calculator works out Resting energy requirement and Daily (maintenance) energy requirement from Body weight, Weight unit and Life stage. The default figures on this page give daily (maintenance) energy requirement of 260 kcal/day; change any entry and the result, the working and the sources update together.
Your figures
Updates as you typeHow this is worked out
4 steps
- Body weight = 4.500 kg
- RER = 70 x 4.500^0.75 = 70 x 3.089651 = 216.28 kcal/day
- MER = 1.2 x RER (Neutered adult, cat) = 259.53 kcal/day
- No food energy density supplied, so no portion was computed.
Its 4 worked examples are re-run on every release, last on 15 September 2026. What changed
Sources and references
2 sources
What the Cat Calorie Calculator calculates
Calculates a dog or cat's resting and daily maintenance energy requirement from body weight and life stage, and converts the result into a daily food portion.
How to use this Cat Calorie Calculator
Enter Body weight, Weight unit, Life stage and Report. Resting energy requirement updates as you type. Change one figure at a time to see what drives the result.
How the result is worked out
Open “How this is worked out” beside the result for the step-by-step calculation behind Resting energy requirement, Daily (maintenance) energy requirement and Daily energy, low end of the range.
The method follows Pet Nutrition Alliance - Calculating Calories Based on Pet Needs (RER = 70 x BWkg^0.75; Table 1 MER factors) and WSAVA Global Nutrition Committee - Nutrition Toolkit.
What you can compare
Change one input at a time to see how it affects Resting energy requirement, Daily (maintenance) energy requirement and Daily energy, low end of the range. The inputs you can vary are Body weight, Weight unit, Life stage, Report, Override the RER factor (optional) and Food energy density.
Understanding Resting energy requirement, Daily (maintenance) energy requirement and Daily energy, low end of the range
Educational estimate only. The published MER factors are starting points - individual animals vary by as much as 50% - and a veterinarian should set the feeding plan, especially for weight loss, growth, gestation or illness.
Results are general information, not financial, tax, legal, medical or engineering advice. Check any decision that matters with a qualified professional.
See something wrong? Report a problem with this calculator
Frequently asked questions
How do I calculate my cat's calorie needs?
Calculates a dog or cat's resting and daily maintenance energy requirement from body weight and life stage, and converts the result into a daily food portion. Open “How this is worked out” beside the result to see each step for your own figures.
Is 200 calories a day good for a cat?
Calculates a dog or cat's resting and daily maintenance energy requirement from body weight and life stage, and converts the result into a daily food portion. On the figures this page opens with — body weight 10 — the daily (maintenance) energy requirement is 260 kcal/day. Put your own figures in their place and the working updates beside the result.
Can a cat survive on 100 calories a day?
It needs Body weight, Weight unit, Life stage, Report, Override the RER factor (optional) and Food energy density. Nothing else is required, and the figures stay in your browser.
What information do I need for the Cat Calorie Calculator?
You need Body weight, Weight unit, Life stage, Report, Override the RER factor (optional), Food energy density, Portion unit and Meals per day. The page opens with default figures that give daily (maintenance) energy requirement of 260 kcal/day, so you can see the scale before entering your own.
What does this Cat Calorie Calculator show?
It shows Resting energy requirement, Daily (maintenance) energy requirement, Daily energy, low end of the range, Daily energy, high end of the range, RER multiplier used, Food per day, Food per meal and Portion unit, with the working and any warnings for your entries.
Can I check how the Cat Calorie Calculator result was calculated?
Yes. The “How this is worked out” section shows the calculation steps, and the sources section identifies the references used for the method.