BMR (Basal Metabolic Rate)
Plain-English definition of BMR (Basal Metabolic Rate) — part of our health & fitness glossary.
Definition
Basal Metabolic Rate is the energy your body uses at complete rest, in calories per day, to keep basic systems running. Total daily energy expenditure (TDEE) is BMR plus calories burned through activity.
Worked example
For a 30-year-old woman, 65 kg, 165 cm: BMR is roughly 1,400 kcal/day using the Mifflin-St Jeor equation. For a 40-year-old man, 85 kg, 180 cm: BMR is roughly 1,800 kcal/day. BMR rises with lean body mass and falls slowly with age — roughly 2% per decade after 30.
Why it matters
Health calculations are most useful as ballpark figures, not prescriptions. BMR and TDEE are estimates based on population averages — they get you within roughly 10–15% of your actual energy needs, which is enough to plan around.
Common mistake
Treating calculator output as exact. Measured metabolic rate varies by 10–20% between individuals of the same age, sex, and weight. Use the number as a starting point and adjust based on two to four weeks of real-world results.
Calculators that use this concept
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See also
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