About the BMR Calculator
Your basal metabolic rate (BMR) is the energy your body uses at complete rest to breathe, circulate blood and keep its temperature. Multiply it by an activity factor and you get your total daily energy expenditure (TDEE), the calories that keep your weight stable.
This calculator uses the Mifflin-St Jeor equation, which the Academy of Nutrition and Dietetics considers the most accurate for most adults, and also shows the revised Harris-Benedict result for comparison. You can enter feet, inches and pounds or centimeters and kilograms.
How to use
- Choose your sex and units, then enter age, height and weight.
- Pick the activity level that matches a typical week.
- Read your BMR and the calories to maintain, lose or gain weight.
- Switch the goal under the macro table to see grams of carbs, protein and fat per day.
Mifflin-St Jeor formula
Men: BMR = 10 ร weight (kg) + 6.25 ร height (cm) โ 5 ร age + 5
Women: BMR = 10 ร weight (kg) + 6.25 ร height (cm) โ 5 ร age โ 161
Example: a 30-year-old man who is 5 ft 9 in (175 cm) and 154 lb (70 kg): 700 + 1,093.75 โ 150 + 5 = 1,649 kcal. With moderate activity (ร1.55) his TDEE is about 2,556 kcal.
| Activity level | Factor |
|---|---|
| Sedentary | 1.2 |
| Lightly active | 1.375 |
| Moderately active | 1.55 |
| Very active | 1.725 |
| Extra active | 1.9 |
Tips for using your numbers
- A deficit of about 500 kcal a day leads to roughly 1 lb (0.45 kg) of weight loss per week. Real results vary because metabolism adapts.
- Most people overestimate their activity level. If unsure, choose one level lower.
- Women generally shouldnโt go below about 1,200 kcal and men below about 1,500 kcal a day without medical supervision.
FAQ
What is the difference between BMR and TDEE?
BMR is what you burn lying still all day. TDEE adds daily movement, exercise and digestion, so it is always higher. To keep your weight stable you need to eat about your TDEE.
How many calories should I eat to lose weight?
A common approach is TDEE minus 500 kcal, which works out to about 1 lb a week. Avoid eating below your BMR for long periods.
How accurate is the BMR calculator?
Mifflin-St Jeor predicts BMR within about 10% for most adults. It can be less accurate for very muscular people or people with obesity, where a body-fat-based formula may fit better.
Is this medical advice?
No. It is an estimate for general information. If you have a medical condition, are pregnant or breastfeeding, or plan a large change in diet, ask a doctor or registered dietitian.