What is my BMR?
Calculate your basal metabolic rate (BMR) to understand daily calorie needs. Plan your nutrition and weight management.
- Your BMR
- 1,783
With the Mifflin-St Jeor (1990) formula, your BMR is about 1,783 calories a day.
- Sedentary or light activity (PAL 1.53)
- 2,728
- Active or moderately active (PAL 1.76)
- 3,138
- Vigorously active (PAL 2.25)
- 4,011
Your BMR: 1,783. With the Mifflin-St Jeor (1990) formula, your BMR is about 1,783 calories a day.
Your BMR by age
This calculator gives general information only. It is not medical advice and does not replace a doctor or other health care provider. Talk with a professional about your results. Terms of use
How to calculate
Estimates basal metabolic rate (calories a day at rest) with the Mifflin-St Jeor, revised Harris-Benedict, or Katch-McArdle equation, and daily energy needs at three activity levels.
Example with the default inputs (Weight 180 lb, Height 5 ft 10 in, Age 30, Body fat 15%, Sex Male, Formula Mifflin-St Jeor (1990)): With the Mifflin-St Jeor (1990) formula, your BMR is about 1,783 calories a day.
Formula: Mifflin-St Jeor: BMR = 10W + 6.25H − 5A + 5 (men) or − 161 (women). Harris-Benedict (Roza and Shizgal 1984): 88.362 + 13.397W + 4.799H − 5.677A (men), 447.593 + 9.247W + 3.098H − 4.330A (women). Katch-McArdle: 370 + 21.6 × W × (1 − body fat ÷ 100). W in kg, H in cm, A in years.
- The equations estimate the energy used at complete rest for healthy adults; a measured value can differ.
- Katch-McArdle uses lean body mass (weight × (1 − body fat ÷ 100)), so it ignores sex, age, and height.
- Daily energy needs are BMR × the physical activity level (PAL) of the FAO/WHO/UNU (2004) examples: 1.53, 1.76, and 2.25.
Worked examples
Each example is checked against the calculator on every build.
- Weight 180 lb, Height 5 ft 10 in, Age 30, Body fat 15%, Sex Male, Formula Mifflin-St Jeor (1990) gives BMR (calories a day) 1,782.716266, Active or moderately active (PAL 1.76) 3,137.580628.Source: Mifflin et al. (1990) men: 10 × 81.6466266 kg + 6.25 × 177.8 cm − 5 × 30 + 5 = 1,782.72
- Weight 132.3 lb, Height 5 ft 5 in, Age 40, Body fat 30%, Sex Female, Formula Mifflin-St Jeor (1990) gives BMR (calories a day) 1,270.25, Sedentary or light activity (PAL 1.53) 1,943.4825.Source: Mifflin et al. (1990) women: 10 × 60 + 6.25 × 165 − 5 × 40 − 161 = 1,270.25
- Weight 154.3 lb, Height 5 ft 8.9 in, Age 30, Body fat 15%, Sex Male, Formula Harris-Benedict (revised 1984) gives BMR (calories a day) 1,695.667.Source: Revised Harris-Benedict (Roza and Shizgal 1984) men: 88.362 + 13.397 × 70 + 4.799 × 175 − 5.677 × 30 = 1,695.67
- Weight 121.3 lb, Height 5 ft 3 in, Age 25, Body fat 25%, Sex Female, Formula Harris-Benedict (revised 1984) gives BMR (calories a day) 1,343.608.Source: Revised Harris-Benedict (Roza and Shizgal 1984) women: 447.593 + 9.247 × 55 + 3.098 × 160 − 4.330 × 25 = 1,343.61
- Weight 176.4 lb, Height 5 ft 10.9 in, Age 30, Body fat 20%, Sex Male, Formula Katch-McArdle gives BMR (calories a day) 1,752.4, Vigorously active (PAL 2.25) 3,942.9.
- BMR (calories a day) 1,800, Height 5 ft 10.9 in, Age 30, Body fat 15%, Sex Male, Formula Mifflin-St Jeor (1990) gives Weight 180.8 lb.
How BMR is worked out
Pick one of three equations. W is weight in kilograms, H is height in centimetres, and A is age in whole years. The calculator converts pounds, feet, and inches for you (1 lb = 0.45359237 kg and 1 in = 2.54 cm, exactly).
Mifflin-St Jeor (1990)
- Men: BMR = 10 × W + 6.25 × H − 5 × A + 5
- Women: BMR = 10 × W + 6.25 × H − 5 × A − 161
Harris-Benedict (1918), as revised by Roza and Shizgal (1984)
- Men: BMR = 88.362 + 13.397 × W + 4.799 × H − 5.677 × A
- Women: BMR = 447.593 + 9.247 × W + 3.098 × H − 4.330 × A
Katch-McArdle
- Lean body mass = W × (1 − body fat ÷ 100)
- BMR = 370 + 21.6 × lean body mass
Katch-McArdle does not use sex, age, or height. The other two do not use body fat. The result is in kilocalories ("calories") a day.
Fill in the other values and leave BMR empty to find it. You can also enter a BMR and leave weight empty: the calculator solves the same equation for the weight that gives that BMR. Height, age, and body fat are always entered (each formula uses only the ones listed above). A solved BMR or weight at or below 0 has no answer.
Daily energy needs
Total daily energy = BMR × physical activity level (PAL). The FAO/WHO/UNU (2004) report classifies lifestyles as sedentary or light activity (PAL 1.40 to 1.69), active or moderately active (1.70 to 1.99), and vigorous or vigorously active (2.00 to 2.40). The calculator uses the report's example PAL values:
| Lifestyle | PAL used |
|---|---|
| Sedentary or light activity | 1.53 |
| Active or moderately active | 1.76 |
| Vigorous or vigorously active | 2.25 |
Assumptions
- The equations are for healthy adults. They estimate energy use at complete rest; a measured value can differ.
- Values are not rounded between steps. The page shows whole calories.
Worked examples by hand
Man, 30, 5 ft 10 in, 180 lb (Mifflin-St Jeor). 180 lb = 81.6466266 kg and 70 in = 177.8 cm. BMR = 10 × 81.6466266 + 6.25 × 177.8 − 5 × 30 + 5 = 816.466 + 1,111.25 − 150 + 5 = 1,782.72 calories a day. At PAL 1.76: 1,782.72 × 1.76 = 3,137.58.
Woman, 40, 165 cm, 60 kg (Mifflin-St Jeor). 10 × 60 + 6.25 × 165 − 5 × 40 − 161 = 600 + 1,031.25 − 200 − 161 = 1,270.25. At PAL 1.53: 1,943.48.
Man, 30, 175 cm, 70 kg (revised Harris-Benedict). 88.362 + 13.397 × 70 + 4.799 × 175 − 5.677 × 30 = 88.362 + 937.79 + 839.825 − 170.31 = 1,695.67.
Woman, 25, 160 cm, 55 kg (revised Harris-Benedict). 447.593 + 9.247 × 55 + 3.098 × 160 − 4.330 × 25 = 447.593 + 508.585 + 495.68 − 108.25 = 1,343.61.
80 kg at 20% body fat (Katch-McArdle). Lean mass = 80 × 0.8 = 64 kg. BMR = 370 + 21.6 × 64 = 1,752.4. At PAL 2.25: 3,942.9.
The weight that gives a BMR of 1,800 (man, 30, 180 cm, Mifflin-St Jeor). W = (1,800 − 6.25 × 180 + 5 × 30 − 5) ÷ 10 = (1,800 − 1,125 + 150 − 5) ÷ 10 = 82 kg.
Other questions people ask
What is BMR (Basal Metabolic Rate)?
BMR is the amount of energy (calories) your body burns at rest to maintain basic life functions like breathing, circulation, cell production, nutrient processing, protein synthesis, and ion transport. It represents the minimum number of calories needed to keep your body functioning while at complete rest.
Which BMR formula should I use?
The Mifflin-St Jeor equation is recommended for most people. A 2005 review by the American Dietetic Association found it the most likely of the common equations to estimate resting energy within 10% of the measured value. The Harris-Benedict equation (1918, revised in 1984) is the traditional formula. The Katch-McArdle formula uses lean body mass, so it suits people who know their body fat percentage.
How accurate are BMR calculations?
BMR calculations are estimates based on statistical data. In the 2005 review above, Mifflin-St Jeor came within 10% of the measured value for most, but not all, healthy adults, and individual variations can be larger due to factors like genetics, muscle mass, and metabolic conditions. For the most accurate results, consider consulting a healthcare professional or using specialized equipment.
What are the activity levels?
Your total daily energy need is BMR × your physical activity level (PAL). The FAO/WHO/UNU (2004) report groups lifestyles as sedentary or light activity (PAL 1.40 to 1.69), active or moderately active (1.70 to 1.99), and vigorous or vigorously active (2.00 to 2.40). The calculator shows the report's example values: 1.53, 1.76, and 2.25.
How does age affect BMR?
BMR typically decreases with age due to loss of muscle mass and changes in body composition. This is why the formulas include age as a factor - older individuals generally have lower metabolic rates than younger people with similar body compositions.
Why is sex included in BMR calculations?
Men typically have higher BMR than women due to generally higher muscle mass and different body composition. The Mifflin-St Jeor and Harris-Benedict formulas have separate versions for men and women. Katch-McArdle uses lean body mass instead.
How does body fat percentage affect BMR?
Muscle tissue is more metabolically active than fat tissue, so individuals with higher muscle mass and lower body fat typically have higher BMR. The Katch-McArdle formula specifically accounts for this by using lean body mass in its calculation.
Can I use BMR for weight loss planning?
Yes, BMR is the starting point. To lose weight, you need to eat fewer calories than your total daily energy need (BMR × activity level). Talk to a doctor or registered dietitian about a safe target for you.
What factors can affect my actual BMR?
Several factors can affect your actual BMR: muscle mass (more muscle = higher BMR), genetics, thyroid function, body temperature, stress levels, pregnancy, certain medications, and extreme dieting (which can lower BMR).
How often should I recalculate my BMR?
Recalculate your BMR when there are significant changes in your weight, body composition, age, or activity level.