Toolstia / Calorie and BMR calculator
Calorie and BMR calculator
Enter your age, sex, weight, height and activity level to estimate your basal metabolic rate (BMR) and how many calories you use each day. Metric and imperial units are both supported.
This is an estimate using the Mifflin-St Jeor equation, not medical advice. Do not eat below the level your doctor recommends. Speak to a doctor or dietitian before changing your diet, especially if you are pregnant, ill or under 18.
How it works
- Choose your units and enter your details.
- Pick your activity level.
- Read your BMR and daily calorie estimates.
What BMR means
Basal metabolic rate is the energy your body uses at complete rest to keep you alive. It does not include moving about, exercise or digesting food.
The equation
The Mifflin-St Jeor equation: 10 x weight (kg) + 6.25 x height (cm) - 5 x age, then +5 for men or -161 for women. Maintenance calories are BMR multiplied by an activity factor from 1.2 to 1.9.
Losing or gaining
The tool shows 500 calories a day below and above maintenance, which is a common starting point for a slow change of roughly half a kilogram a week. Real results vary from person to person.
An estimate only
Equations are averages. Muscle mass, health conditions, medication and other factors change the real number, so treat the result as a starting point and adjust from what actually happens.
Questions
Is this medical advice?
No. Speak to a doctor or dietitian before changing your diet, especially if you are pregnant, unwell or under 18.
Why can't I enter an age under 15?
The equation is for adults, and children's needs are different.
How accurate is it?
It is an estimate, and individual differences can be significant.
Is my data stored?
No. It stays in your browser.