Calorie Calculator
Estimate daily calories (TDEE) from the Mifflin-St Jeor equation.
Frequently asked questions
How are daily calorie needs calculated?
The tool estimates your basal metabolic rate with the Mifflin-St Jeor equation, then multiplies by an activity factor to get your total daily energy expenditure.
What is the Mifflin-St Jeor equation?
It estimates BMR from weight, height, age and sex, and is widely regarded as one of the more accurate equations for everyday use.
What is the difference between BMR and TDEE?
BMR is the energy your body uses at complete rest, while TDEE is your BMR multiplied by an activity level to include daily movement and exercise.
How do I use this to lose weight?
Eating fewer calories than your TDEE creates a deficit, and a common target of about 500 fewer calories a day aims for roughly one pound of loss per week.
How do I gain weight or build muscle?
Eating more calories than your TDEE creates a surplus, so the tool can suggest a target above maintenance to support weight or muscle gain.
Why does activity level matter so much?
Activity level can change the estimate by hundreds of calories, since a very active person burns far more than someone who is mostly sedentary.
Are these numbers exact?
No. They are general estimates, and individual needs vary, so this is not medical or nutritional advice.
Is my personal data uploaded?
No. The calculation happens entirely in your browser and your age, weight and height are never sent anywhere.