BMRHarrisBenedictEquation
Calculate Basal Metabolic Rate using the Harris-Benedict equation for men and women. Enter weight, height, age, and activity level to estimate daily calorie needs for weight management and fitness goals.
About This Calculator
The BMR (Harris-Benedict) Calculator estimates your Basal Metabolic Rate — the number of calories your body burns at complete rest — using the original Harris-Benedict equation developed in 1919. This formula, based on a landmark study by Harris and Benedict published in the Proceedings of the National Academy of Sciences, remains one of the most trusted methods for estimating resting energy expenditure worldwide.
Your BMR represents the minimum energy your body needs for essential functions like breathing, circulation, cell production, and temperature regulation. By multiplying your BMR by an activity factor (1.2 for sedentary to 1.9 for very active), you get your Total Daily Energy Expenditure (TDEE) — the actual calories you burn each day including physical activity. This makes the Harris-Benedict calculator an essential tool for athletes, fitness enthusiasts, dietitians, and anyone managing their weight.
How the Formula Works
For Men: BMR = 66.5 + (13.75 × weight in kg) + (5.003 × height in cm) − (6.75 × age in years)
For Women: BMR = 655.1 + (9.563 × weight in kg) + (1.850 × height in cm) − (4.676 × age in years)
Then, TDEE = BMR × Activity Factor where activity factors are: Sedentary (1.2), Light (1.375), Moderate (1.55), Active (1.725), Very Active (1.9).
Regional Notes
India: The Indian Council of Medical Research (ICMR) recommends using BMR-based calculations for dietary planning. Typical BMR for Indian adults ranges from 1,200-1,600 cal/day for women and 1,400-1,800 cal/day for men.
United States: The Dietary Guidelines for Americans use BMR as the foundation for estimating calorie needs. The average US adult female BMR is ~1,400 cal/day and male BMR is ~1,700 cal/day.
United Kingdom: The NHS and British Dietetic Association recommend BMR-based TDEE calculations for weight management. Average UK adult BMR values are similar to US ranges with adjustments for population demographics.
Frequently Asked Questions
How do I calculate my BMR using the Harris-Benedict equation?
For men: BMR = 66.5 + (13.75 x weight in kg) + (5.003 x height in cm) - (6.75 x age). For women: BMR = 655.1 + (9.563 x weight in kg) + (1.850 x height in cm) - (4.676 x age). Multiply your BMR by your activity factor (1.2 sedentary to 1.9 very active) to get your total daily energy expenditure (TDEE).
What is the difference between BMR and TDEE?
Basal Metabolic Rate (BMR) is the number of calories your body needs at complete rest for basic functions like breathing and circulation. Total Daily Energy Expenditure (TDEE) is your BMR multiplied by an activity factor — it represents your total calorie burn including physical activity, exercise, and digestion.
How accurate is the Harris-Benedict equation?
The original Harris-Benedict equation (1919) is one of the most widely used BMR formulas. It is approximately 70-80% accurate for the general population. The Mifflin-St Jeor equation is considered slightly more accurate for modern populations.
How do I use BMR to lose weight in India?
Calculate your BMR then multiply by your activity level to get TDEE. To lose weight, eat 300-500 calories below your TDEE. For Indian diets, focus on reducing refined carbs and oil while maintaining protein intake. Consult a dietitian before starting any weight loss plan.
How do I use BMR to lose weight in the US?
Calculate your BMR then multiply by your activity level to find maintenance calories. A deficit of 500 calories per day typically leads to about 1 pound of weight loss per week. Use the MyPlate guidelines and consult a registered dietitian for personalized advice.
How do I use BMR to lose weight in the UK?
Work out your BMR then multiply by your PAL (Physical Activity Level). The NHS recommends a daily deficit of 500-600 calories for steady weight loss of 0.5-1 kg per week. Follow the Eatwell Guide and consult your GP before starting any diet.
What factors affect my BMR?
Age, sex, weight, height, and body composition all affect BMR. Muscle mass increases BMR, while aging and fat mass decrease it. Hormonal factors, genetics, and certain medical conditions like hypothyroidism can also influence your metabolic rate.
Is the original or revised Harris-Benedict equation better?
This calculator uses the original Harris-Benedict equation (1919). The revised version (1984 by Roza and Shizgal) used updated coefficients. Both are valid, with the original remaining widely used in clinical settings and fitness applications globally.