Estimated resting energy requirement, not a minimum calorie-intake prescription.
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BMR Formulas Compared
Different formulas can produce different answers because they were developed from different datasets and use different inputs. This calculator makes that disagreement visible rather than hiding it.
Male: 10W + 6.25H − 5A + 5
Female: 10W + 6.25H − 5A − 161Male: 88.362 + 13.397W + 4.799H − 5.677A
Female: 447.593 + 9.247W + 3.098H − 4.330A370 + 21.6 × lean body mass (kg)Weight × (1 − body fat % ÷ 100)W = weight in kilograms, H = height in centimeters, A = age in years.
BMR vs. RMR vs. TDEE
BMR refers to basal energy expenditure under strict resting conditions. Resting metabolic rate (RMR/REE) is closely related but is generally measured under less restrictive resting conditions. Predictive equations are commonly used to estimate resting energy expenditure when direct measurement is unavailable.
TDEE is different: it attempts to estimate total daily energy expenditure, including energy beyond rest. That is why an activity multiplier is not applied to the main BMR result on this page.
BMR Calculator FAQ
Which BMR formula should I use?
No predictive equation measures your individual metabolism directly. Mifflin-St Jeor is used here as the primary general estimate, while Revised Harris-Benedict is shown for comparison. If you provide body-fat percentage, Katch-McArdle adds a lean-mass-based comparison. Differences between formulas are expected.
Why do BMR calculators give different results?
Calculators may use different equations, rounding rules and inputs. Predictive equations were developed from population data, so they can also differ from measured resting energy expenditure for an individual.
Does Katch-McArdle require body-fat percentage?
Yes. It estimates lean body mass from body weight and body-fat percentage. If the body-fat estimate is inaccurate, the resulting Katch-McArdle estimate will also be affected.
Is BMR the number of calories I should eat?
No. BMR is an estimate of resting energy expenditure, not a personalized calorie-intake recommendation. Daily energy needs also include activity and other components of energy expenditure.
What is the difference between BMR and TDEE?
BMR focuses on resting energy needs. TDEE estimates total daily expenditure and therefore requires additional assumptions about activity and movement.
Methodology context: NCBI/Endotext Mifflin-St Jeor resting metabolic rate table and NCBI Dietary Reference Intakes discussion of resting energy expenditure. This calculator is informational and is not medical advice.