Health

🔥 Calorie Calculator

Work out how many calories you actually burn in a day — your BMR and your TDEE — and what that means for losing or gaining weight.

—BMR (at rest)
—Maintenance
—Lose ~0.5 kg/week
—Gain ~0.25 kg/week

BMR is what your body burns at complete rest. Maintenance (TDEE) multiplies that by how active you are. A deficit of about 500 kcal a day is the usual target for roughly 0.5 kg (1 lb) of fat loss a week — but do not eat below your BMR, and speak to a doctor before aggressive dieting.

About the Calorie Calculator

Every calorie target starts with one number: how much energy your body uses in a day. That figure has two parts. The first is your basal metabolic rate, the cost of simply staying alive, which depends mostly on body size, sex and age. The second is everything you do on top of that — walking, working, training — expressed as a multiplier on the first.

Multiplying the two gives your total daily energy expenditure, or maintenance calories. Eat around that number and your weight holds steady; eat below it and you lose; eat above it and you gain. The arithmetic here uses the Mifflin-St Jeor equation, the formula most clinical dietitians default to because it is more accurate than the older Harris-Benedict equation across a wide range of body types. Both metric and imperial inputs are accepted — for anything else that needs converting between the two systems, the unit converter covers length, weight, volume and temperature.

Frequently asked questions

What is the difference between BMR and TDEE?

BMR (basal metabolic rate) is the energy you would burn lying still all day — it covers breathing, circulation, temperature control and cell repair. TDEE (total daily energy expenditure) is BMR multiplied by an activity factor, and it is the number that predicts whether you gain, lose or hold weight. If you eat roughly your TDEE, your weight stays put.

How many calories should I eat to lose weight?

A deficit of about 500 kcal a day below your maintenance level is the standard target, and it produces roughly 0.5 kg (1 lb) of loss a week — which is also what this calculator's weight-loss figure shows. Larger deficits lose weight faster but cost muscle and are harder to sustain.

How accurate is the Mifflin-St Jeor equation?

It is the equation most dietitians use, and studies find it lands within about 10% of measured resting energy expenditure for most adults. That still means a few hundred calories either way. Treat the result as a starting point, watch your weight over two to three weeks, and adjust.

Is it safe to eat only 1,200 calories a day?

1,200 kcal is generally treated as the floor below which you should not go without medical supervision, because it becomes very hard to hit your protein, vitamin and mineral needs. This calculator will not show a weight-loss target below that level.

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