BMR Calculator: Calories You Burn at Rest
Find your basal metabolic rate with three proven formulas side by side, and see how it turns into your total daily calories.
What is BMR?
Your basal metabolic rate (BMR) is the number of calories your body needs to stay alive if you did nothing but lie still for 24 hours. It pays for breathing, pumping blood, keeping your brain and organs running and holding your body temperature steady.
For most people, BMR makes up about 60 to 70% of all the calories they burn in a day. That makes it the biggest single part of your metabolism, and the starting point for every calorie target.
BMR formulas used in this calculator
There is no single perfect BMR equation. We show three, so you can see how much they agree for your body.
Mifflin-St Jeor
RecommendedPublished in 1990. The most accurate equation for most healthy adults in a major review of prediction formulas.
Women: 10W + 6.25H − 5A − 161
Harris-Benedict
Revised 1984The classic 1919 equation, updated in 1984. Tends to give slightly higher numbers than Mifflin-St Jeor.
Women: 447.593 + 9.247W + 3.098H − 4.330A
Katch-McArdle
Uses body fatBased on lean body mass, so it ignores age and sex. Often the most accurate for lean or very muscular people.
LBM = W × (1 − body fat %)
W = weight in kg, H = height in cm, A = age in years, LBM = lean body mass in kg.
What affects your BMR?
Muscle uses more energy at rest than fat, so more muscle means a higher BMR.
Bigger and taller bodies have more tissue to maintain and burn more.
BMR drifts down slowly with age, largely because of muscle loss and lower activity.
Men usually have a higher BMR than women of the same size because they carry more muscle.
Thyroid hormones have a strong effect. An underactive thyroid can lower BMR noticeably.
Eating far below your needs for months can lower your burn a little. See metabolic adaptation.
BMR vs TDEE vs RMR
- Measures
- Energy at complete rest, measured after sleep and fasting
- Use it as
- The base of your calorie needs
- Measures
- Almost the same as BMR, with less strict test conditions
- Use it as
- Interchangeable with BMR in everyday use
- Measures
- BMR plus digestion, daily movement and exercise
- Use it as
- Your maintenance calories
BMR examples (Mifflin-St Jeor)
| Person | Age | Height | Weight | BMR |
|---|---|---|---|---|
| Woman | 25 | 163 cm (5 ft 4 in) | 60 kg (132 lb) | 1,333 kcal |
| Woman | 45 | 165 cm (5 ft 5 in) | 75 kg (165 lb) | 1,395 kcal |
| Man | 30 | 178 cm (5 ft 10 in) | 80 kg (176 lb) | 1,768 kcal |
| Man | 55 | 175 cm (5 ft 9 in) | 90 kg (198 lb) | 1,724 kcal |
Can you increase your BMR?
A little. Building muscle through strength training is the most reliable way, and eating enough protein helps you keep it. “Metabolism boosting” foods and supplements have tiny effects at best. Most of the difference you can make to your daily burn comes from daily movement, which our guide to NEAT explains.
BMR calculator FAQs
What is a normal BMR?
Most adult women have a BMR between about 1,200 and 1,500 calories and most adult men between about 1,500 and 1,900. Taller, heavier and more muscular people are higher.
Which BMR formula is the most accurate?
Mifflin-St Jeor is the most accurate for the general population. Katch-McArdle can be better if you know your body fat percentage and are leaner or more muscular than average.
Is BMR the same as calories burned per day?
No. BMR is only what you burn at rest. Your total daily burn (TDEE) is usually 1.2 to 1.9 times higher, depending on how active you are.
Does a higher BMR mean faster weight loss?
A higher BMR means you can eat more for the same deficit, but weight loss still depends on eating fewer calories than your total daily burn.
How accurate is a BMR calculator?
For most healthy adults the estimate is within about 10% of a lab measurement. It can be further off if you have unusual muscle mass or a medical condition that affects metabolism.