BMR Calculator · Practical guide
How Many Calories Does My Body Burn at Rest?
Your resting burn — your BMR — is typically 1,200 to 2,000 calories a day, set by your size, age, and sex.
At a glance
The Short Answer
Most adults burn between 1,200 and 2,000 calories per day at complete rest. This figure is your basal metabolic rate (BMR), and it covers breathing, circulation, body temperature, and cell maintenance — roughly 60-75% of everything you burn in a day. The calculator above pins down your exact number from your age, height, weight, and sex.
Interactive tool
BMR Calculator
Enter your own values, then compare the result with the examples below.
Daily Calorie Needs by Activity
| Activity Level | Multiplier | Calories / Day |
|---|---|---|
| Sedentary (little/no exercise) | 1.2 | -- |
| Lightly active (1-3 days/week) | 1.375 | -- |
| Moderately active (3-5 days/week) | 1.55 | -- |
| Very active (6-7 days/week) | 1.725 | -- |
| Super active (physical job/training) | 1.9 | -- |
What Sets Your Number
The Mifflin-St Jeor equation weights four factors: every 10 kg of body weight adds about 100 kcal, every 10 cm of height adds about 62.5 kcal, every year of age subtracts 5 kcal, and men average about 166 kcal more than women of the same build (the +5 versus −161 constant). Bigger, younger, and male all push the number up.
A Worked Example
A 40-year-old man at 85 kg and 178 cm burns 850 + 1,112.5 − 200 + 5 ≈ 1,768 kcal/day at rest. A woman with identical stats burns about 1,602 kcal. Neither figure includes any movement — that is what activity multipliers add on top.
Rest Burn Is Not Your Eating Target
Your BMR is the floor, not the plan. Daily life adds movement, so total daily needs run 1.2 to 1.9 times your BMR — the 1,768 kcal example becomes 2,122 kcal sedentary or 2,740 kcal with moderate exercise. Eating at or below your BMR for long stretches risks muscle loss and metabolic slowdown.
Frequently Asked Questions
Is sleeping calorie burn the same as BMR?
Sleep burn runs slightly below BMR because metabolism dips overnight, but BMR is measured after a full night's sleep and a 12-hour fast, so the two are close.
Do I burn calories just by existing?
Yes. Your organs, brain, and muscles consume energy around the clock; the brain alone accounts for roughly 20% of resting burn.
Why do men burn more calories at rest than women?
Mainly because men average more lean muscle mass and larger organs at the same weight, and muscle burns more calories at rest than fat.
Can I raise my resting calorie burn?
Building muscle through strength training raises it modestly, and avoiding crash diets prevents it from dropping. There is no food or supplement that meaningfully boosts BMR.