BMR calculator (basal metabolic rate)
Basal metabolic rate (BMR) is the calories your body burns at rest. Below is your TDEE by activity level (BMR × factor).
BMR (Mifflin-St Jeor)
Fill in all fields — the result appears automatically
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- BMR (Harris-Benedict)
- — kcal/day
- Sedentary
- — kcal/day
- Lightly active
- — kcal/day
- Moderately active
- — kcal/day
- Very active
- — kcal/day
- Extra active
- — kcal/day
This calculator is for informational purposes only and is not medical advice. Consult a doctor or qualified professional before changing your diet or training.
What BMR is and how to calculate it
BMR (basal metabolic rate) is the calories your body burns at complete rest for breathing, circulation and organ function. The calculator computes BMR with two formulas — Mifflin-St Jeor (more accurate today) and Harris-Benedict (the classic) — then multiplies it by an activity factor to give your total daily expenditure (TDEE).
BMR FAQ
Mifflin-St Jeor or Harris-Benedict — which is more accurate?
Mifflin-St Jeor (1990) is more accurate for most people. Harris-Benedict (1919) is the historic classic and reads slightly high.
How is BMR different from TDEE?
BMR is your at-rest burn. TDEE is your full daily burn: BMR multiplied by an activity factor from 1.2 (sedentary) to 1.9 (heavy training plus a physical job).
How do I use BMR to lose weight?
Work out your TDEE and eat at a 15–20% deficit. Staying below your BMR for long isn’t advised — it slows metabolism and costs muscle.