BMR Calculator

Estimate your Basal Metabolic Rate (BMR) — the calories your body burns at complete rest — using the Mifflin-St Jeor equation. Enter sex, age, weight and height in metric or imperial.

Choose your unit system, then enter your sex, age, weight and height. The Mifflin-St Jeor equation estimates the energy your body uses at rest, plus a sedentary daily total.

BMR (calories/day at rest)
Daily needs (sedentary)

Your Basal Metabolic Rate (BMR) is the energy your body uses just to stay alive — breathing, circulation, cell production — at complete rest. It's the baseline onto which activity is added to find your total daily needs.

Mifflin-St Jeor

  • Men: 10 × kg + 6.25 × cm − 5 × age + 5
  • Women: 10 × kg + 6.25 × cm − 5 × age − 161

Multiply BMR by an activity factor for total daily energy expenditure (TDEE); 1.2 represents a sedentary day.

Examples

  • Male, 30, 70 kg, 175 cm: BMR ~1649 kcal
  • Female, 28, 60 kg, 165 cm: BMR ~1314 kcal
  • BMR falls with age and falls as you lose weight

Frequently asked questions

Is Mifflin-St Jeor the best formula?

It's among the most accurate for the general population without body-composition data. Katch-McArdle is more precise if you know your lean body mass, as it uses fat-free mass.

Why is my BMR lower than I expected?

Most people underestimate body fat and overestimate muscle. BMR is driven mostly by lean mass; crash dieting can also temporarily suppress it. The figure is an estimate, not an exact measurement.

Just for the giggles, much love.
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