BMR Calculator: Basal Metabolic Rate
Enter your sex, age, weight and height to estimate how many calories your body burns at complete rest in a day.
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Formula
Mifflin-St Jeor equation, with weight in kilograms, height in centimetres and age in years:
- Men:
BMR = 10 × weight + 6.25 × height − 5 × age + 5 - Women:
BMR = 10 × weight + 6.25 × height − 5 × age − 161
Pounds are converted at 0.45359237 kg per pound and inches at 2.54 cm per inch. The result is an estimate in kilocalories per day.
Worked example
A 30-year-old man weighing 80 kg and 180 cm tall: 10 × 80 = 800, 6.25 × 180 = 1125, 5 × 30 = 150, so 800 + 1125 − 150 + 5 = 1780 kcal per day.
Frequently asked questions
What is BMR?
Basal metabolic rate is the energy your body uses at complete rest to keep breathing, circulating blood and maintaining temperature. It does not include movement or digesting food.
Which formula does this BMR calculator use?
The Mifflin-St Jeor equation: 10 × weight in kg + 6.25 × height in cm − 5 × age, then +5 for men or −161 for women. For a 30-year-old man at 80 kg and 180 cm that is 800 + 1125 − 150 + 5 = 1780 kcal a day.
How accurate is the result?
It is an estimate. Studies find Mifflin-St Jeor within about 10 percent of measured resting energy use for most healthy adults, but muscle mass, genetics and health conditions change the real figure. It is not medical advice.
Is BMR the same as the calories I should eat?
No. BMR is only the resting part. Multiply it by an activity factor to get your daily total: 1780 × 1.55 = 2759 kcal for moderate exercise. Use the TDEE calculator for that step.