◐Free calculator

Calorie calculator

Estimate your daily calorie needs from your age, sex, height, weight and activity level – and see targets for losing or gaining weight.

Sex
Calories to maintain your weight
—
kcal / day
Lose ~0.25 kg (½ lb) a week
Lose ~0.5 kg (1 lb) a week
Gain ~0.25 kg (½ lb) a week
Basal metabolic rate (BMR)

Calculated instantly in your browser — nothing you enter is sent or stored.

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How to use the calorie calculator

  1. Choose your sex and enter your age.
  2. Enter your weight and height in metric or imperial units.
  3. Pick the activity level that best describes a normal week.

The big number is your estimated maintenance calories: the amount that keeps your weight stable. Below it are targets for gentle weight loss, weight loss and weight gain.

How it works

First the calculator estimates your basal metabolic rate (BMR) – the energy your body uses at rest – with the Mifflin–St Jeor equation, which is widely used by dietitians:

Men: BMR = 10 × kg + 6.25 × cm − 5 × age + 5

Women: BMR = 10 × kg + 6.25 × cm − 5 × age − 161

It then multiplies the BMR by an activity factor (from 1.2 for sedentary to 1.9 for very active) to get your total daily energy expenditure (TDEE).

Worked examples

A 35-year-old woman, 165 cm, 65 kg, moderately active

BMR = 650 + 1,031.25 − 175 − 161 = 1,345 kcal. × 1.55 = about 2,085 kcal a day to maintain her weight.

A 40-year-old man, 180 cm, 85 kg, lightly active

BMR = 850 + 1,125 − 200 + 5 = 1,780 kcal. × 1.375 = about 2,448 kcal a day.

Losing or gaining weight

A deficit of about 500 kcal a day leads to a loss of roughly 0.5 kg (about 1 lb) per week, because a kilogram of body fat stores around 7,700 kcal. Slower changes are easier to keep up and protect muscle. Most experts advise women not to go below about 1,200 kcal and men not below about 1,500 kcal a day without medical supervision – the calculator warns you if a target is lower.

These are estimates for healthy adults. Needs differ with body composition, health conditions, pregnancy and medication. For personal advice, talk to a doctor or registered dietitian.

Frequently asked questions

What is the difference between BMR and TDEE?
BMR is the energy your body needs at complete rest. TDEE adds the energy you use for daily activity and exercise, so it is always higher than BMR.
How many calories should I eat to lose weight?
A common starting point is your maintenance calories minus 500 a day, which leads to about 0.5 kg (1 lb) of weight loss per week. Adjust after a few weeks based on your real results.
How accurate is the Mifflin–St Jeor equation?
For most adults it is within about 10% of measured values, which makes it one of the more reliable formulas. Very muscular or very overweight people may get less accurate results.

Last reviewed: November 13, 2026

Results are estimates for general information only and are not financial, tax, medical or legal advice. Check important figures with a qualified professional.