Calorie calculator
Estimate the energy you burn and targets for changing weight.
About this calculator
This estimates how much energy you use in a day from your age, sex, height, weight and activity level, then shows targets for slow weight change.
It is an estimate, and individuals can differ from it. Speak to a doctor or dietitian before a large change in diet, especially if you are pregnant or have a health condition.
How it works
Uses the Mifflin-St Jeor equation for resting burn, multiplied by an activity factor.
Worked example
- Units: Metric
- Sex: Female
- Age: 35 years
- Height: 170 cm
- Weight: 70 kg
- Activity: Light exercise, 1 to 3 days a week
To maintain your weight: 1,961 kcal (a day)
The story behind it
Where the idea came from: Mark Mifflin, Sachiko St Jeor and colleagues, 1990.
Scientists have estimated resting energy use from body size since the Harris-Benedict equation of the early 1900s. In 1990, Mifflin, St Jeor and their colleagues published a newer equation based on a study of healthy adults. It's the one this calculator uses for resting burn, before multiplying by how active you are.
Why you can trust this calculator
- It runs in your browser. Nothing you type into it is sent anywhere.
- The method is explained on this page, so you can check it yourself.
- Free to use, with no sign-up.
- Results are estimates, not medical advice.
- Spotted a mistake? Tell us and we'll look into it.
After 15 years as a mathematics educator, I built CalculStore to give students, teachers, professionals and anyone working with numbers simple, reliable tools.
Meet the founder