Calorie calculator
Your daily calorie needs are the intake at which your weight stays the same. The calculator estimates them from your sex, age, weight, height and activity, and shows the ranges for losing weight and for gaining muscle.
What you burn in a day has four parts: basal metabolism (the largest), the energy spent digesting food, everyday movement, and exercise. The formula works out the first part; a single activity factor stands in for the other three.
That factor is where most of the uncertainty comes from. Two people with the same weight and the same job can differ by several hundred kilocalories a day in everyday movement alone.
How it works
- Get an estimate from the formula and your activity factor.
- Eat at roughly that intake for two to three weeks without changing your habits.
- Compare your average weight week by week: any drift is the correction your own numbers need.
Where the calories go
Exercise is usually the smallest part of daily expenditure, and everyday movement the most underrated. Half an hour of cleaning burns about 120 kcal at 70 kg, and over a week such episodes add up to more than three workouts.
For weight loss the calculator shows a deficit of 10–20% of your needs; for muscle gain, a surplus of 5–10%.
| Part of daily expenditure | What it is |
|---|---|
| Basal metabolism | energy used at rest, the largest part |
| Thermic effect of food | energy spent on digestion, about 10% of intake |
| Everyday movement | steps, housework, stairs |
| Exercise | usually less than it seems |
Frequently asked questions
- How many calories do I need a day?
- As many as you burn: at that intake your weight stays the same. The calculator estimates it from basal metabolism and an activity factor; your weight over two to three weeks shows how close the estimate is.
- Why does my real intake differ from the calculated one?
- The formula covers only basal metabolism, and the activity factor estimates the rest. Everyday movement alone can differ by several hundred kilocalories a day between two similar people.
- How many calories should I cut to lose weight?
- A deficit of 10–20% of your needs is a common range. The calculator shows it for your numbers and does not suggest an intake below 1,200 kcal for women or 1,500 kcal for men.
Further reading
- Daily calorie intake: how it is calculated and where the formula goes wrong
- Calorie deficit: how to calculate it and how to hold it
- Metabolism: can it be “boosted”?
More calculators: TDEE calculator, BMI calculator, Ideal weight calculator, Body fat calculator.
This calculator gives an estimate for general information. It is not medical advice, a diagnosis, or a prescription for treatment or a diet, and it does not replace a consultation with your doctor. If you have a health condition, are pregnant, take medication, or follow a diet prescribed to you, decisions about food belong with your doctor.