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Calorie Calculator

Estimate how many calories your body uses each day, and how many to eat to maintain, lose or gain weight.

How it works

First the calculator finds your basal metabolic rate (BMR), the energy your body uses at complete rest, with the Mifflin-St Jeor equation:

• Men: BMR = 10 × weight in kg + 6.25 × height in cm − 5 × age + 5
• Women: BMR = 10 × weight in kg + 6.25 × height in cm − 5 × age − 161

BMR is then multiplied by an activity factor, from 1.2 for a desk job with little exercise to 1.9 for hard daily training. The result is your total daily energy expenditure, the calories needed to keep your weight steady.

Worked example

A 30-year-old man who weighs 70 kg, is 175 cm tall and exercises lightly has a BMR of 10 × 70 + 6.25 × 175 − 5 × 30 + 5 = 1,649 kcal. Multiplied by 1.375, he needs about 2,267 kcal a day to maintain his weight, or about 1,767 kcal a day to lose roughly 0.5 kg (1 lb) a week.

Losing or gaining weight safely

• A deficit of about 500 kcal a day leads to roughly 0.5 kg (1 lb) of weight loss a week for most people.
• Very low intakes are hard to sustain and can lose muscle. Many health services advise not going below about 1,200 kcal a day for women or 1,500 for men without medical supervision.
• Protein, sleep and strength training help keep muscle while you lose fat.
• Your needs drop as you lose weight, so recalculate every few kilograms.

Choosing an activity level

Most people overestimate how active they are. If you are unsure, pick the lower level, track your weight for two to three weeks, and adjust by 100 to 200 kcal a day based on the trend.

Frequently asked questions

How accurate is this calorie calculator?

Mifflin-St Jeor is one of the most accurate everyday formulas, usually within about 10% for most people, but your real needs can differ.

What is the difference between BMR and TDEE?

BMR is the energy you burn at complete rest. TDEE adds the energy used in daily movement and exercise.

Should I eat back calories burned in exercise?

Your activity level already includes regular exercise, so you do not need to add it again.

Can I use this calculator if I am pregnant?

No. Calorie needs change during pregnancy and breastfeeding, so ask your doctor or midwife.

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