BMR Calculator
Estimate your Basal Metabolic Rate — the calories your body burns at rest — from your sex, age, height and weight, using the Mifflin-St Jeor equation.
Estimate for general information only — not medical or nutritional advice. BMR equations give an approximation that varies with body composition, genetics and health. Consult a professional before making big diet changes.
What your BMR means
Your Basal Metabolic Rate is the energy your body uses at complete rest — keeping your heart, lungs, brain and cells running. It’s the biggest slice of your daily calorie burn, before any movement. This calculator uses the well-validated Mifflin-St Jeor equation: 10 × weight(kg) + 6.25 × height(cm) − 5 × age, then +5 for men or −161 for women.
From BMR to daily calories
On its own, BMR doesn’t tell you how much to eat — you also burn calories moving and exercising. Multiply BMR by an activity factor to get your TDEE (maintenance calories), or use the calorie calculator to turn it into targets for losing or gaining weight. For a quick weight check, see the BMI calculator.
Frequently asked questions
What is BMR?
Your Basal Metabolic Rate is the number of calories your body needs at complete rest just to keep working — breathing, circulation, cell repair. It is the largest part of your daily calorie burn, before any activity is added.
How is BMR calculated?
This calculator uses the Mifflin-St Jeor equation: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5 for men (−161 for women). It converts US units for you. For example, a 30-year-old man, 5′9″, 160 lbs has a BMR of about 1,650 kcal/day.
What is the difference between BMR and TDEE?
BMR is your calorie burn at rest. TDEE (Total Daily Energy Expenditure) is BMR multiplied by an activity factor to account for movement and exercise — it is the number you actually need to maintain your weight.