Calorie Calculator
Estimate how many calories you burn per day — BMR and maintenance calories with the Mifflin–St Jeor equation.
This is an estimate for healthy adults based on the Mifflin–St Jeor equation; actual needs vary from person to person. It is not medical or dietary advice — talk to a doctor or dietitian about your own needs.
About this tool
Enter sex, age, height, weight and how active you are. The calculator estimates your basal metabolic rate (BMR) with the Mifflin–St Jeor equation and multiplies it by a standard activity factor to estimate the calories you need per day to keep your weight. You also see the result in kilojoules and for every activity level. For healthy adults; an estimate, not medical advice.
Frequently asked questions
First the BMR: for women 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161; for men the same with +5 instead of −161. Then multiply by an activity factor from 1.2 (sedentary) to 1.9 (very active). A 35-year-old woman of 165 cm and 65 kg has a BMR of 1,345 kcal; moderately active (× 1.55) that is about 2,085 kcal a day.
Basal metabolic rate is the energy your body uses at complete rest — breathing, circulation, keeping warm. It is usually the largest part of daily energy use. A 40-year-old man of 180 cm and 80 kg has an estimated BMR of 10 × 80 + 6.25 × 180 − 5 × 40 + 5 = 1,730 kcal.
A 2005 systematic review in the Journal of the American Dietetic Association found it more likely than the other common equations to land within 10% of measured resting metabolic rate in healthy adults. Individual errors still happen, so treat the result as a starting point.
Sedentary (× 1.2) is desk work and little exercise; lightly active (× 1.375) is light exercise 1–3 days a week; moderately active (× 1.55) 3–5 days; active (× 1.725) hard exercise 6–7 days; very active (× 1.9) physical work plus training. Most people overestimate, so if unsure pick the lower level.
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