BMR Calculator
Your basal metabolic rate plus estimated daily calories at every activity level — using the Mifflin-St Jeor or Harris-Benedict equation.
Reviewed by the OmniCalc teamMethod verified 2026-07-01
1,649kcal/day
BMR 1,649 kilocalories per day- Sedentary — little or no exercise
- 1,979 kcal/day
- Light — exercise 1–3 days/week
- 2,267 kcal/day
- Moderate — exercise 3–5 days/week
- 2,556 kcal/day
- Active — hard exercise 6–7 days/week
- 2,844 kcal/day
- Very active — hard exercise + physical job
- 3,133 kcal/day
- BMR (at rest)
- 1,649
Informational only — not medical or dietary advice. Predictive equations estimate an average; individual metabolism varies. Talk to a clinician or dietitian before changing how you eat.
The two BMR formulas
Both equations predict resting energy expenditure in kilocalories per day from your weight, height, age and sex. This calculator works in metric (kg, cm); imperial inputs elsewhere on the site convert to metric before the formula is applied.
Mifflin-St Jeor (default)
men: BMR = 10·kg + 6.25·cm − 5·age + 5
women: BMR = 10·kg + 6.25·cm − 5·age − 161
Mifflin MD, St Jeor ST, et al. “A new predictive equation for resting energy expenditure in healthy individuals.” Am J Clin Nutr. 1990;51(2):241–247.
Revised Harris-Benedict
men: BMR = 88.362 + 13.397·kg + 4.799·cm − 5.677·age
women: BMR = 447.593 + 9.247·kg + 3.098·cm − 4.330·age
Roza AM, Shizgal HM. “The Harris Benedict equation reevaluated: resting energy requirements and the body cell mass.” Am J Clin Nutr. 1984;40(1):168–182.
Activity multipliers (TDEE)
Total daily energy expenditure multiplies your BMR by a physical-activity factor. The calculator shows all five so you can pick the one that matches a typical week.
| Activity level | Multiplier |
|---|---|
| Sedentary — little or no exercise | × 1.2 |
| Light — exercise 1–3 days/week | × 1.375 |
| Moderate — exercise 3–5 days/week | × 1.55 |
| Active — hard exercise 6–7 days/week | × 1.725 |
| Very active — hard exercise + physical job | × 1.9 |
Standard physical-activity-level (PAL) factors applied to BMR, popularised alongside the Harris-Benedict equation; see FAO/WHO/UNU, Human energy requirements (2001).
Frequently asked questions
What's the difference between BMR and TDEE?
BMR (basal metabolic rate) is the energy your body burns completely at rest, just to keep you alive. TDEE (total daily energy expenditure) is BMR multiplied by an activity factor, so it estimates the calories you actually use across a normal day — the number to compare against what you eat.
Which formula should I use — Mifflin-St Jeor or Harris-Benedict?
Mifflin-St Jeor (1990) is generally considered the most accurate predictive equation for the modern general population, which is why it's the default. The revised Harris-Benedict (Roza & Shizgal, 1984) is a well-established alternative and usually lands within a few percent. Neither uses body-fat percentage, so both are estimates.
How accurate is a BMR estimate?
Predictive equations estimate the average for people of your age, sex, height and weight — real individuals can vary by 10% or more depending on muscle mass, hormones and genetics. Use the number as a starting point, then adjust based on how your weight actually trends over a few weeks.
Should I eat exactly my BMR to lose weight?
No — eating at or below BMR long-term is usually too little. Weight change is driven by the gap between what you eat and your TDEE (the activity-adjusted number), not BMR alone. Any deliberate calorie deficit is best planned with a clinician or registered dietitian.
Sources: Mifflin-St Jeor (1990) and revised Harris-Benedict (Roza & Shizgal, 1984). This tool is informational and not a substitute for medical or dietary advice. Last reviewed 2026-07-01.