BMR Calculator
Calculate your Basal Metabolic Rate (BMR) — the calories your body burns at complete rest.
Did this tool work for you?
How to use this calculator
The Mifflin-St Jeor equation is the most accurate BMR formula for most adults.
- 1
Enter your weight in kilograms.
- 2
Enter your height in centimetres.
- 3
Enter your age in years.
- 4
Select your biological sex.
- 5
Select your typical activity level.
- 6
The result shows your BMR (calories at rest) and TDEE (total daily energy expenditure).
Frequently asked questions
What is BMR?
BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest — just to keep organs functioning (breathing, circulation, cell repair). It accounts for 60–75% of total daily calorie burn.
What is TDEE?
TDEE (Total Daily Energy Expenditure) is your BMR multiplied by an activity factor. It represents the total calories you burn per day including all activity. Eating at TDEE maintains weight; below TDEE causes weight loss; above TDEE causes weight gain.
Why is the Mifflin-St Jeor formula used?
Multiple studies have found the Mifflin-St Jeor equation to be the most accurate BMR formula for the general population, typically within 10% of measured values. It is more accurate than the older Harris-Benedict equation.
How accurate is this calculator?
BMR formulas are population averages. Individual BMR can vary by 10–15% due to genetics, muscle mass, health conditions, and medication. For precise measurement, a metabolic test (indirect calorimetry) is required.
BMR and daily calorie needs
BMR vs TDEE
BMR is the minimum calories to sustain life at rest. TDEE adds activity on top. A sedentary person's TDEE ≈ BMR × 1.2. A very active person's TDEE ≈ BMR × 1.9. Most adults have a TDEE between 1,600 and 3,000 kcal/day.
Using BMR for weight management
To lose 0.5 kg/week: eat 500 kcal below TDEE (1 lb ≈ 3,500 kcal). To lose 1 kg/week: eat 1,000 kcal below TDEE. Never eat below your BMR — it triggers metabolic adaptation and muscle loss. A deficit of 500–750 kcal/day is safe for most people.
Factors that affect BMR
Muscle mass (muscle burns more calories than fat), age (BMR declines ~2% per decade after 20), body size, gender (men typically have higher BMR due to more muscle mass), thyroid function, and ambient temperature all affect metabolic rate.
Learn more from an authoritative source:
CDCCalorie Calculator
Calculate your daily calorie needs to lose weight, maintain, or gain weight based on your stats and activity.
Body Fat Calculator
Estimate your body fat percentage using the US Navy method with waist, neck, and hip measurements.
Ideal Weight Calculator
Calculate your ideal body weight range using four leading medical formulas — Devine, Robinson, Miller, and Hamwi.
Water Intake Calculator
Calculate your recommended daily water intake based on your weight, activity level, and climate.
Heart Rate Calculator
Calculate your maximum heart rate and target heart rate zones for fat burning, cardio, and peak performance.
Protein Calculator
Calculate your daily protein intake recommendation based on your weight, goal, and activity level.
Results are estimates for informational purposes only and do not constitute professional financial, medical, legal, or technical advice. Read full disclaimer →