BMR Calculator (Basal Metabolic Rate)

Calories your body burns at rest, plus daily calories for each activity level.

With the Mifflin-St Jeor equation, BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5 for men, or − 161 for women. A 30-year-old man who weighs 80 kg and is 180 cm tall has a BMR of about 1,780 kcal a day.

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How to use it

  1. Choose sex and enter age, weight and height in metric or US units.
  2. Optionally add body fat percentage to get the Katch-McArdle estimate.
  3. Read your BMR and the maintenance calories for your activity level.

What you enter

What you get

Formula

Men: BMR = 10W + 6.25H − 5A + 5 | Women: BMR = 10W + 6.25H − 5A − 161 | Katch-McArdle: 370 + 21.6 × lean mass (kg)

W is weight in kg, H is height in cm and A is age in years.

Worked example

Input: Man, 30 years, 80 kg, 180 cm

Result: BMR ≈ 1,780 kcal/day; TDEE ≈ 2,760 kcal at moderate activity

Eating about 2,760 kcal a day would maintain weight at 3–5 workouts a week.

Questions

What is BMR?

Basal metabolic rate is the energy your body uses at complete rest to breathe, circulate blood and keep organs working. It is usually 60–70% of the calories you burn in a day.

Which BMR formula is most accurate?

Mifflin-St Jeor is the most accurate for most adults, typically within 10% of measured values. Katch-McArdle can be better for lean, muscular people if you know your body fat percentage.

How do I turn BMR into daily calories?

Multiply BMR by an activity factor: 1.2 sedentary, 1.375 light, 1.55 moderate, 1.725 very active, 1.9 athlete. The result is your total daily energy expenditure (TDEE).

Is BMR the same as RMR?

Nearly. BMR is measured under strict fasting, rested conditions; resting metabolic rate is measured less strictly and runs slightly higher. The equations here estimate both.

Limitations

References

More Health & Wellness

All free tools · By Dr. Zubair Khalid, DVM, MS, PhD.