BMR Calculator
Estimate your Basal Metabolic Rate — the calories your body burns at rest — from age, sex, height and weight. Free and private, in your browser.
Report a problemThis is an estimate of the energy your body uses at complete rest — it is a guide, not medical advice. Your real needs vary with activity, muscle, genetics and health. Talk to a health professional before making big changes.
How to use
- Choose metric (kilograms and centimetres) or imperial (pounds, feet and inches) and pick your sex.
- Type your age, weight and height. Your BMR updates live as you type — there is nothing to submit.
- Pick a formula if you like: Mifflin-St Jeor is the modern default, Harris-Benedict is the older revised one. The big number is the calories you burn each day at rest.
FAQ
What is BMR and what does the number mean?
BMR stands for Basal Metabolic Rate — the calories your body uses just to keep you alive at complete rest, with no activity at all: breathing, circulation, keeping your organs running and your temperature steady. It is the floor of your daily energy use. To get the calories you actually burn in a day, you multiply BMR by an activity factor (about 1.2 for very little movement up to roughly 1.9 for hard daily training). This calculator gives you the resting baseline using your age, sex, height and weight.
Which formula should I use, Mifflin-St Jeor or Harris-Benedict?
Mifflin-St Jeor is the more accurate choice for most people today and is the recommended default. The revised Harris-Benedict equation is the classic older formula and usually gives a slightly higher number. They are close for typical body types, so either is a reasonable estimate.
Is anything I type sent to a server?
No. Your age, sex, height and weight are used for plain arithmetic right in your browser — nothing is uploaded or stored. The calculator works offline and keeps your numbers private. Remember this is an estimate, not medical advice.