About this calculator
Your calorie needs depend on your body, your age, and how much you actually move. The Mifflin-St Jeor equation is the most widely used modern formula, replacing the outdated Harris-Benedict equation from the early twentieth century.
How it works
BMR estimates calories burned at complete rest. Multiplying by an activity factor gives total daily energy expenditure. Adjusting that number by a deficit or surplus gives a practical target. The activity factor is the biggest source of error, so pick honestly.
Frequently asked questions
What is my BMR?
Basal metabolic rate is the calories your body burns at rest to keep basic functions going. Mifflin-St Jeor estimates it as 10×weight in kg + 6.25×height in cm − 5×age, plus 5 for men and minus 161 for women.
What is TDEE?
Total daily energy expenditure is BMR multiplied by an activity factor, representing the calories you burn in a typical day including movement and exercise. Maintaining weight means eating roughly your TDEE.
How many calories should I eat to lose weight?
Most people need around a 550 calorie daily deficit to lose roughly 0.5 kg, or 1 lb, per week. That works out to about 3,850 calories per week, which matches the widely observed one pound per week rule.
Which activity level should I choose?
Be honest rather than aspirational. If you sit at a desk all day and exercise occasionally, sedentary or light is correct. Overestimating activity is the most common reason a calculated target fails to produce results.
Why does my weight loss stall after a few weeks?
As you lose weight, TDEE falls because you weigh less. A target set at your starting weight becomes too high intake over time. Recalculating every 10 kg of loss keeps progress moving.
Do I need to count calories forever?
No. Many people use tracking to build awareness for a few months, then rely on portion control and habitual choices. It also matters that your deficit comes partly from movement and food quality, not only from eating less.