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🫀 BMR Calculator

Calculate your Basal Metabolic Rate using clinically validated equations

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BMR (Basal Metabolic Rate) — Quick answer

Basal Metabolic Rate (BMR) is the daily calorie expenditure at complete rest. It is the foundation for total daily energy expenditure (TDEE) calculations.

Mifflin-St Jeor: Men: BMR = 10W + 6.25H − 5A + 5
Women: BMR = 10W + 6.25H − 5A − 161
TDEE: TDEE = BMR × activity factor

Worked example: Male, 30 years, 70 kg, 175 cm, moderately active. Mifflin BMR = 10×70 + 6.25×175 − 5×30 + 5 = 700 + 1,093.75 − 150 + 5 = 1,648.75 kcal/day. TDEE = 1,649 × 1.55 = 2,556 kcal/day.

BMR by age and weight (Mifflin-St Jeor, male, 175 cm)

Age60 kg70 kg80 kg90 kg
201,5291,6291,7291,829
301,4791,5791,6791,779
401,4291,5291,6291,729
501,3791,4791,5791,679
601,3291,4291,5291,629

Standard / source: Mifflin-St Jeor (1990) is the most accurate equation for non-athletic adults; Harris-Benedict (1919, revised 1984) and Katch-McArdle (lean body mass) are alternatives.

Used for: Weight-loss meal planning, sports nutrition, clinical dietetics, fitness coaching, intermittent-fasting protocol design.

TDEE activity factor table (applied to Mifflin-St Jeor BMR)

Your TDEE = BMR × activity factor. The five standard multipliers (1.2, 1.375, 1.55, 1.725, 1.9) are the physical-activity-level (PAL) factors used with the Mifflin-St Jeor and Harris-Benedict equations:

Activity level Factor Description Exercise / week
Sedentary1.2Little or no exercise, desk job0 days
Lightly active1.375Light exercise or sports1–3 days
Moderately active1.55Moderate exercise or sports3–5 days
Very active1.725Hard exercise / physical job6–7 days
Extra active1.9Very hard exercise + physical job or 2×/day trainingDaily, intense

Source: physical-activity-level (PAL) multipliers used with Mifflin MD, St Jeor ST et al. (1990), A new predictive equation for resting energy expenditure, Am J Clin Nutr 51(2):241–247, and the FAO/WHO/UNU PAL framework. Example: a 1,650 kcal BMR at "moderately active" (1.55) → TDEE ≈ 2,558 kcal/day.

🫀 BMR Calculator

Formula

This calculator uses the standard bmr calculator formula:

Mifflin-St Jeor (women)
BMR = 10 × weight + 6.25 × height − 5 × age − 161

Frequently Asked Questions

What is BMR?

Basal Metabolic Rate (BMR) is the number of calories your body needs to maintain basic life-sustaining functions (breathing, circulation, cell production) at complete rest.

Which BMR formula is more accurate: Mifflin-St Jeor or Harris-Benedict?

The Mifflin-St Jeor equation (1990) is widely considered more accurate for most people than the original Harris-Benedict equation (1919). The revised Harris-Benedict (1984) is also reliable.

What is the difference between BMR and TDEE?

BMR is calories at complete rest. TDEE (Total Daily Energy Expenditure) multiplies BMR by an activity factor to estimate actual daily calorie needs.

Does BMR decrease with age?

Yes. BMR typically decreases by about 2% per decade after age 20, primarily due to loss of muscle mass (sarcopenia). Strength training can help maintain BMR.

How can I increase my BMR?

Building muscle mass through resistance training is the most effective way to increase BMR, as muscle tissue burns more calories at rest than fat tissue.

Is BMR affected by body weight?

Yes. Higher body weight generally means higher BMR because larger bodies require more energy for basic functions. Lean body mass has a stronger correlation with BMR than total weight.

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