Calorie Calculator
Estimate how many calories you need each day to maintain your weight, and how many to lose or gain weight, based on your age, size, and activity level.
| Age | years |
| Gender | |
| Height | |
| Weight | |
| Activity |
Result
Your daily calorie estimates will appear here.
How it works
Daily needs are estimated from your BMR (a standard resting-calorie equation) multiplied by an activity factor. Weight loss and gain targets assume roughly 0.25 kg (0.5 lb) to 0.5 kg (1 lb) per week. Very low calorie diets may not be appropriate for everyone.
How it works
Daily calorie needs are estimated from BMR (calories at rest) multiplied by an activity factor (TDEE). Targets for weight loss/gain adjust from maintenance.
Formula
- Estimate BMR (e.g. a standard resting-calorie equation), then TDEE ≈ BMR × activity factor.
- Weight change targets use an energy deficit/surplus (often ~500 kcal/day as a rough guide for ~0.5 kg/week), but individual response varies.
Assumptions
- Estimates only. Needs vary by body composition, health, and lifestyle. Very low-calorie diets and medical conditions need professional guidance.
General information only, not medical or nutrition advice.
How to use the Calorie Calculator
It takes a few seconds, and every figure is calculated in your browser.
- Enter your age.
- Select your gender.
- Enter your height.
- Enter your weight.
- Pick your activity level.
- Press Calculate — the result appears in the dark panel beside the form.
- Use Copy, CSV, Share or Print under the result if you want to keep it.
Calorie Calculator — frequently asked questions
What formula does the Calorie Calculator use?
Estimate BMR (e.g. a standard resting-calorie equation), then TDEE ≈ BMR × activity factor. Weight change targets use an energy deficit/surplus (often ~500 kcal/day as a rough guide for ~0.5 kg/week), but individual response varies.
How does the Calorie Calculator work?
Daily needs are estimated from your BMR (a standard resting-calorie equation) multiplied by an activity factor. Weight loss and gain targets assume roughly 0.25 kg (0.5 lb) to 0.5 kg (1 lb) per week. Very low calorie diets may not be appropriate for everyone.
What assumptions and limitations should I know about?
Estimates only. Needs vary by body composition, health, and lifestyle. Very low-calorie diets and medical conditions need professional guidance.
Last updated 10 November 2026 · Formula, worked example and assumptions are documented above, and every result is calculated in your browser.