Calorie Calculator

Estimated daily calorie needs.

Estimate your basal metabolic rate and daily calorie needs (Mifflin-St Jeor formula) from your stats and activity level.

How it works

Your basal metabolic rate (BMR) is estimated with the Mifflin-St Jeor equation, based on weight, height, age and sex. It's then multiplied by an activity factor to estimate total daily energy expenditure.

When it helps

A common starting point for understanding roughly how much energy your body uses in a day.

The Mifflin-St Jeor formula

Your basal metabolic rate (BMR) — the energy your body uses at complete rest — is estimated with the Mifflin-St Jeor equation: 10 × weight in kg + 6.25 × height in cm − 5 × age, plus 5 for men or minus 161 for women. It was published in 1990 and is generally considered one of the more reliable equations for healthy adults.

Your total daily energy expenditure (TDEE) is the BMR multiplied by an activity factor: 1.2 for sedentary, 1.375 for light activity, 1.55 for moderate, 1.725 for active and 1.9 for very active.

A worked example

A 30-year-old man who is 180 cm tall and weighs 80 kg has a BMR of 10 × 80 + 6.25 × 180 − 5 × 30 + 5 = 1,780 kcal. With moderate activity, his estimated daily needs are 1,780 × 1.55 ≈ 2,759 kcal. If he were mostly sedentary, the same body would need about 2,136 kcal.

Using the number sensibly

Treat the result as a starting estimate rather than an exact target — real needs vary by a few hundred calories between people with the same stats. A practical approach is to eat around the estimate for two or three weeks, watch how your weight trends, and adjust. Most people also overestimate their activity level, so if you're unsure between two levels, the lower one is usually closer.

Frequently asked questions

How accurate is it?

It's an estimate and can be off for many individuals. A doctor or dietitian can give personalized advice.

What is BMR?

The energy your body uses at complete rest to keep vital functions running.

How many calories should I cut to lose weight?

A moderate deficit of roughly 300–500 kcal below your TDEE is a common starting point. Very large deficits are hard to sustain; for personal advice, speak to a doctor or registered dietitian.

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