Basal Metabolic Rate (BMR) Calculator
Basal metabolic rate is the energy your body uses at complete rest for breathing, circulation and temperature. Compare results from three established formulas.
Your details
kcal / day · Mifflin-St Jeor
- Harris-Benedict1,430 kcal
- Katch-McArdleenter body fat
- Sedentary (×1.2)1,644 kcal
- Lightly active (×1.375)1,884 kcal
- Moderately active (×1.55)2,124 kcal
- Very active (×1.725)2,364 kcal
- Extra active (×1.9)2,603 kcal
BMR formulas
Mifflin-St Jeor is the most recommended equation today. The revised Harris-Benedict (1984) is older but still common. Katch-McArdle uses lean body mass, so it can be more accurate for people who know their body fat and have high muscle mass.
Mifflin-St Jeor Men: 10 × kg + 6.25 × cm − 5 × age + 5 Women: 10 × kg + 6.25 × cm − 5 × age − 161 Harris-Benedict (revised) Men: 88.362 + 13.397 × kg + 4.799 × cm − 5.677 × age Women: 447.593 + 9.247 × kg + 3.098 × cm − 4.330 × age Katch-McArdle 370 + 21.6 × lean mass (kg)
What affects BMR?
- Muscle mass: muscle burns more energy at rest than fat.
- Age: BMR tends to fall with age, largely due to muscle loss.
- Sex: men usually have higher BMR due to more muscle.
- Body size: larger bodies use more energy.
- Hormones and health: thyroid function, fever and some medicines change BMR.
From BMR to daily calories
BMR alone is not your daily need. Multiply it by an activity factor, or use the Calorie Calculator directly.
| Level | Description | Factor |
|---|---|---|
| Sedentary | Desk job, no exercise | 1,2 |
| Lightly active | Exercise 1–3 days/week | 1,375 |
| Moderately active | Exercise 3–5 days/week | 1,55 |
| Very active | Exercise 6–7 days/week | 1,725 |
| Extra active | Hard training or physical job | 1,9 |
Frequently asked questions
What is a normal BMR?
Roughly 1200–1500 kcal for adult women and 1500–1900 kcal for men is common, depending on size, age and muscle.
How can I raise my BMR?
Building muscle with resistance training is the most effective way. Adequate protein and avoiding very low-calorie diets also help.
Which BMR formula is most accurate?
Mifflin-St Jeor is most consistent for the general population; Katch-McArdle can be better if you reliably know your body fat.
Is eating only my BMR harmful?
Eating below BMR for long periods can cause fatigue, muscle loss and deficiencies. Weight-loss targets are usually set slightly below TDEE instead.