Estimate resting metabolic rate using Mifflin-St Jeor and optionally Katch-McArdle formulas, with a comparison to approximate strict BMR.
Share this calculator
Also in Energy & Metabolism
Health & Nutrition
Resting metabolic rate (RMR) is the number of calories your body burns at rest while awake. It is the most practical baseline for daily energy budgeting and is typically 9–11% higher than the strictly fasted, supine basal metabolic rate (BMR) measured in laboratory conditions.
BMR is defined under tightly controlled conditions: complete rest, lying flat, fully fasted, and thermoneutral environment. RMR is measured at rest while awake and is slightly higher because of the energy cost of maintaining alertness. Most online calculators labelled "BMR" actually return an RMR estimate because the Mifflin-St Jeor equation was validated against RMR measurements.
The Mifflin-St Jeor equation (1990) is recommended by the Academy of Nutrition and Dietetics as the most accurate predictive equation for most adults. Men: RMR = 10W + 6.25H − 5A + 5; Women: RMR = 10W + 6.25H − 5A − 161 (W = kg, H = cm, A = years).
Frequently asked questions
RMR is calories burned at rest. Total Daily Energy Expenditure (TDEE) multiplies RMR by an activity factor to account for movement, exercise, and digestion. TDEE is what you need to eat to maintain weight; RMR is the floor.
Katch-McArdle uses lean body mass (LBM) instead of total weight. Because muscle is more metabolically active than fat, people with higher muscle mass will get a higher estimate from Katch-McArdle than from weight-based equations.
Related
These related calculators come from the same leaf category, nearby sibling categories, or the same top-level topic.
Estimate basal metabolic rate from age, sex, height, and weight with Mifflin-St Jeor, Harris-Benedict, and optional Katch-McArdle comparisons.
Estimate total daily energy expenditure from age, body size, sex, and activity level, then compare maintenance, cutting, and bulking calories.
Estimate BMR, maintenance calories, target intake, and daily macro guidance for weight loss, maintenance, or muscle gain in one practical calorie calculator.
Calculate BMR and TDEE using the original Harris-Benedict, revised Harris-Benedict, and Mifflin-St Jeor equations, with activity-level multipliers.
