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BMR Calculator. Energy burned at rest.

Basal metabolic rate from age, sex, weight and height using the Mifflin-St Jeor equation — the floor underneath your daily calorie burn, with nothing added for activity.

Live calculation

What do you burn at rest?

Sex
yrs
lb
in
Basal Metabolic Rate 1,462 kcal/day
Per hour
61 kcal
Per week
10,237 kcal

weight = 72.6 kg, height = 167.6 cm
BMR = 10 × 72.6 + 6.25 × 167.6 − 5 × 30 − 161 = 1,462 kcal/day

Your figures are kept on this device only.

How it works

Basal metabolic rate is the energy your body needs just to keep essential functions running — breathing, circulation, cell repair — while lying still and not digesting anything. It's not how many calories you burn in a day; it's the floor underneath that number. This calculator uses the Mifflin-St Jeor equation, widely regarded as the most accurate BMR formula in general use today.

BMR (male) = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5
BMR (female) = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161

BMR on its own is mostly useful as a building block: multiply it by an activity factor to get total daily energy expenditure (TDEE), the number that actually reflects how many calories you burn in a real day including movement and exercise. See the Calorie / TDEE Calculator to take that next step.

Worked example

A 30-year-old woman, 160 lb, 5'6" (66 in).

Step by step
  1. Convert to metric: 160 lb = 72.6 kg, 66 in = 167.6 cm.
  2. BMR = 10 × 72.6 + 6.25 × 167.6 − 5 × 30 − 161 = 1,462 kcal/day.

At complete rest, this profile burns about 1,462 kcal/day — roughly 61 kcal/hour.

Common questions

How accurate is a BMR formula?

Mifflin-St Jeor is considered the most reliable equation in general population studies, but any formula is still an estimate — actual metabolic rate varies with muscle mass, genetics, hormones and other factors a formula can't see. Treat the result as a solid starting point, not a lab measurement.

What's the difference between BMR and TDEE?

BMR is energy at complete rest. TDEE adds an activity factor on top of BMR to account for movement, exercise and daily life — it's almost always the more useful number for planning calorie intake. The Calorie / TDEE Calculator carries this same BMR forward into that calculation.

Why does the formula need weight and height in kilograms and centimetres?

Mifflin-St Jeor was published using metric units. This calculator converts imperial entries to metric internally before applying it — switching locale only changes which units you type in, not the underlying formula.