BMR Calculator
Calculate your Basal Metabolic Rate (BMR) — the calories your body burns at complete rest — using the Mifflin-St Jeor equation. Enter your sex, age, weight, and height to see your daily resting calorie needs.
Formula
Male: BMR = 10×weight + 6.25×height − 5×age + 5
Female: BMR = 10×weight + 6.25×height − 5×age − 161
- BMR is the number of calories your body needs at complete rest to keep basic functions running — breathing, circulation, and cell repair.
- The Mifflin-St Jeor equation is the most accurate for the general population: men add 5, women subtract 161.
- Weight is in kg, height in cm, and age in years.
- To estimate total daily calories, multiply your BMR by an activity factor (1.2 sedentary up to ~1.9 very active) — that gives your TDEE.
- BMR rises with more muscle and falls with age, so use it as a personalised starting point for calorie planning.
Male, 30 years, 75 kg, 175 cm
Inputs
- Sex: male
- Age: 30 years
- Weight: 75 kg
- Height: 175 cm
BMR = 10×75 + 6.25×175 − 5×30 + 5 = 1,699 kcal/day at complete rest.
Frequently asked questions
What is BMR?
Basal Metabolic Rate is the energy your body uses at complete rest to maintain vital functions like breathing and circulation — roughly 60–70% of daily calorie use.
How is BMR different from TDEE?
BMR is calories at rest. TDEE (Total Daily Energy Expenditure) multiplies BMR by an activity factor to include movement and exercise.
Why use the Mifflin-St Jeor equation?
It is widely regarded as the most accurate predictive formula for resting metabolism in the general adult population.
How can I use my BMR?
Multiply it by an activity factor for your daily needs, then eat below that to lose weight or above it to gain.
Why does BMR fall with age?
Muscle mass tends to decline with age and lean tissue burns more energy than fat, so resting metabolism gradually decreases.
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