How to use the BMR Calculator
- Choose your units.
- Enter your sex, age, height and weight.
- Read your BMR from two established equations.
What does this tool do?
Basal metabolic rate is the energy your body needs just to keep you alive at rest — breathing, circulation, temperature and cell repair. It usually makes up 60–70% of the calories you burn in a day.
BMR falls slightly with age and is higher in people with more muscle mass.
Why use it?
- Two formulas to compare.
- Results in kcal and kJ.
- Starting point for planning your diet.
Example
A 30-year-old man, 180 cm and 80 kg: BMR = 10 × 80 + 6.25 × 180 − 5 × 30 + 5 = 1,780 kcal a day.
The formula
Mifflin–St Jeor: 10 × kg + 6.25 × cm − 5 × age + 5 (men) / − 161 (women)
Revised Harris–Benedict (men): 88.362 + 13.397 × kg + 4.799 × cm − 5.677 × age
Revised Harris–Benedict (women): 447.593 + 9.247 × kg + 3.098 × cm − 4.330 × age
Accuracy and limits
- This is a general estimate for healthy adults, not medical advice. Talk to a doctor or registered dietitian about your own situation.
Privacy
The calculation happens instantly in your browser. The numbers you enter are not sent to our servers or saved. There's no account to create and nothing to install.
Last reviewed by the M2Toolkit team.