BMR & Calorie Calculator
Calculate your Basal Metabolic Rate and daily calorie needs.
Updated April 2026 · CalcFlow Editorial
What is a BMR & Calorie? A BMR calculator uses the Mifflin-St Jeor equation to estimate the calories your body burns at complete rest, then multiplies by an activity factor to give your Total Daily Energy Expenditure (TDEE) — the number of calories needed to maintain your current weight.
Rule of Thumb
A general estimate: multiply your body weight in pounds by 15 for a moderately active person. To lose weight, subtract 500 calories per day from your TDEE to lose approximately 1 lb per week.
Example Calculation
A 35-year-old male, 180 lbs, 5'10", lightly active: BMR = 1,882 kcal/day. TDEE at light activity (BMR x 1.375) = 2,588 kcal/day. To lose 1 lb/week, target 2,088 kcal/day.
Key Facts
- •The Mifflin-St Jeor equation is considered the most accurate for most people, endorsed by the Academy of Nutrition and Dietetics.
- •BMR accounts for 60-75% of total daily calorie expenditure for sedentary individuals (Harvard Health, 2024).
- •A 500-calorie daily deficit creates roughly a 1 lb/week weight loss; a 1,000-calorie deficit targets 2 lbs/week.
- •Muscle tissue burns approximately 6 kcal/lb/day at rest, versus fat tissue at 2 kcal/lb/day, making lean mass a key factor in BMR.
How to Use
- Enter your weight, height, and age.
- Select biological sex.
- Select your activity level.
- Click Calculate to see your BMR and daily calorie targets.
Formula
BMR (Mifflin-St Jeor) = 10 x weight(kg) + 6.25 x height(cm) - 5 x age + 5 (men) or -161 (women)