Calorie Calculator
Estimate how many calories your body uses each day, and a sensible daily target to maintain, lose or gain weight.
How your calorie needs are worked out
Your resting burn from weight, height, age and sex, times how active you are.
- 1
Weight and height
10 × 65 kg
+ 6.25 × 165 cm
= 1,681 - 2
Age and sex
1,681 − 5 × 30
− 161 = 1,370 kcal - 3
Add your activity
1,370 × 1.375
= 1,884 kcal - 4
Pick a target
1,884 − 275
≈ 1,610 kcal
to lose 0.25 kg a week
Read more: the formula, a worked example and safe targets
Your body uses energy even at rest, to breathe, keep warm and keep your organs working. That's your basal metabolic rate (BMR). This calculator estimates it with the Mifflin–St Jeor equation, one of the most accurate formulas for adults, then multiplies it by your activity level.
BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5 (male) or − 161 (female)
Worked example
A 30-year-old woman who is 165 cm tall and weighs 65 kg has a BMR of 650 + 1,031 − 150 − 161 = 1,370 kcal. With light exercise (× 1.375) she uses about 1,880 kcal a day.
Changing your weight gently
Eating about 250–500 kcal less than you use each day leads to a gradual loss of roughly 0.25–0.5 kg a week, which is easier to keep up and kinder to your body than crash diets. This calculator won't suggest going below 1,200 kcal (women) or 1,500 kcal (men) a day, because very low intakes make it hard to get the nutrients you need without medical supervision.
These are estimates; individual needs vary by up to 10–20%. They're not suitable for pregnancy, breastfeeding, under-18s or anyone with a medical condition. Talk to a doctor or registered dietitian before making big changes to how you eat.