Body & weight · Free · Private
Calorie needs calculator — BMR and maintenance calories
Estimate your basal metabolic rate and the calories you need to maintain your weight at different activity levels, using the Mifflin–St Jeor equation.
The formula
We use the Mifflin–St Jeor equation: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age (years), plus 5 for males or minus 161 for females. BMR is then multiplied by an activity factor to estimate total daily energy expenditure — the calories that would keep your weight roughly stable.
Choosing your activity level
- Sedentary: desk job and little planned exercise.
- Lightly active: light exercise 1–3 days a week.
- Moderately active: moderate exercise 3–5 days a week.
- Very active: hard exercise 6–7 days a week.
- Extra active: a physical job plus training, or training twice a day.
Most people overestimate their activity. If unsure, choose one level lower.
Using the number sensibly
Food quality matters as much as quantity: plenty of vegetables, fruit, whole grains, beans, nuts and lean protein supports energy, fullness and long-term health. Large or rapid changes to how much you eat are best planned with a doctor or registered dietitian, especially during pregnancy or breastfeeding, for teenagers, for older adults, and for anyone with diabetes, kidney disease or a history of disordered eating.
Frequently asked questions
What is BMR?
Basal metabolic rate is the energy your body uses at complete rest to keep you alive — breathing, circulation, temperature and cell repair. It is usually the largest part of daily energy use.
How accurate is this calculator?
The Mifflin–St Jeor equation is one of the more accurate formulas for adults, but any individual estimate can be off by a few hundred calories a day. Use it as a starting point and adjust based on how your weight responds over several weeks.
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