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
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.
Frequently asked questions
Is BMR the number of calories I should eat?
No. BMR is what your body burns at complete rest. Your daily needs are higher once you include movement and exercise — use the Calorie Calculator to get that total.
Which BMR formula is the most accurate?
For most adults the Mifflin–St Jeor equation is one of the most accurate, which is why it's used here. Every formula is an estimate, though; your real BMR can differ by around 10%.
Last reviewed by the M2Toolkit team.