Calorie Calculator
Estimate daily calories for your goal.
Your calorie needs depend on your body and how much you move, not on a one-size number. Enter your age, sex, height, weight, and activity level, and this tool estimates your basal metabolic rate with the Mifflin-St Jeor equation, then your daily needs for maintenance, weight loss, and weight gain. Treat the result as a starting point, not medical advice, and adjust based on real results over a few weeks.
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About Calorie Calculator
The number of calories you need in a day is not a fixed figure. It depends on your size, your sex, your age, and how active you are. This calculator starts from the Mifflin-St Jeor equation, the standard formula researchers use to estimate basal metabolic rate, the energy your body uses at rest.
It then multiplies that base rate by an activity factor, from sedentary to extra active, to estimate total daily energy expenditure. From there it shows three targets: a modest deficit for weight loss, maintenance, and a modest surplus for weight gain. The deficit and surplus are 500 calories, the common rule of thumb for about a pound a week.
These are estimates, not prescriptions. Bodies vary, activity trackers overestimate, and food labels have error bars. Use the number as a starting point, track your weight for a few weeks, and adjust up or down based on what actually happens.
How to use Calorie Calculator
- Enter your age, sex, height, and weight.
- Pick your activity level.
- Choose your goal: lose, maintain, or gain weight.
- Click Calculate to see your daily calorie targets.
Why use this tool?
- Uses the Mifflin-St Jeor equation
- Targets for loss, maintenance, and gain
- Metric and imperial units
- Free with no account or signup
Tips for best results
- Weigh yourself weekly under the same conditions to judge the target.
- If weight stalls for 3 weeks, adjust the target by 100 to 200 calories.
- Pick the honest activity level, not the aspirational one.
- Protein and sleep matter as much as the calorie number.