Curious how many calories your body burns doing absolutely nothing? Here is how to calculate your BMR at home: enter your age, height, weight and activity level to get your basal metabolic rate plus daily calorie needs — using the trusted Mifflin-St Jeor equation. Free, no signup, results in seconds.
What is BMR?
Your Basal Metabolic Rate is the energy your body needs just to stay alive — keeping your heart beating, lungs breathing and cells repairing while you lie completely still. For most people it makes up 60–70% of all calories burned in a day. Everything else — walking, working, exercising, even digesting food — sits on top of it.
How to Calculate Your BMR at Home: The Mifflin-St Jeor Equation
Nutrition professionals trust the Mifflin-St Jeor formula because it has proven the most accurate for typical adults:
- Men: (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5
- Women: (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161
Muscle burns more than fat at rest, which is why two people of the same weight can have different BMRs — but for planning purposes, this equation is the gold standard.
BMR vs TDEE: which number matters?
BMR is your floor; TDEE (Total Daily Energy Expenditure) is your real life. Multiply BMR by an activity factor (1.2 for a desk job up to 1.9 for athletes) and you get the calories that maintain your current weight. Want to lose weight? Eat moderately below TDEE. Want to gain muscle? Eat slightly above it with enough protein. Never stay below your BMR for long without medical supervision — that is the energy your organs need to function.
Frequently asked questions
What is BMR?
BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest to keep you alive — breathing, circulation, cell repair. It typically accounts for 60–70% of daily calorie burn.
How is BMR calculated?
This calculator uses the Mifflin-St Jeor equation, considered the most accurate for the general population: it combines your weight, height, age and sex into a daily calorie figure.
What is the difference between BMR and TDEE?
BMR is calories burned at rest. TDEE (Total Daily Energy Expenditure) is BMR plus everything you do — moving, working, exercising. TDEE is the number that matters for weight goals.
How many calories should I eat to lose weight?
A common guideline is eating about 500 calories below your TDEE per day for roughly 0.5 kg of fat loss per week. Never eat below your BMR for long without medical guidance.
Is this BMR calculator free?
Yes. It is 100% free with no signup required.
How can I calculate my BMR at home without equipment?
To calculate your BMR at home without equipment, use the Mifflin-St Jeor equation with just your age, height, weight and sex — no lab test needed. Enter those four numbers above and this calculator applies the formula instantly.
What is a normal BMR for my age and weight?
A normal BMR depends on your age, weight, height and sex: most adults fall between 1,200 and 2,000 calories per day at rest. Calculate your BMR at home with the tool above to see your personal number, then compare it with your total daily calorie needs.