Calorie Calculator
Estimate how many calories you need each day to maintain your weight, plus the targets to lose or gain weight. Enter your details and results update as you type — nothing is uploaded.
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Fill in your details to see your daily calories.
This is for general information only and is not medical or nutritional advice — talk to your doctor or a dietitian. Estimates use the Mifflin–St Jeor equation and standard activity factors, which are averages and won't fit everyone. Don't drop below about 1,200 calories a day (women) or 1,500 (men) without medical supervision.
How to use the calorie calculator
Choose your units, then enter your age, sex, height, weight, and how active you are. Your maintenance calories appear instantly, along with target calories to lose or gain weight — there's no button to press and nothing is sent anywhere.
Activity level. Be honest about how much you move. Picking a level higher than your real activity inflates the estimate and makes weight loss harder than the numbers suggest.
Everything runs in your browser — the numbers you type are never uploaded.
How daily calories are worked out
The calculator first estimates your basal metabolic rate (BMR) — the calories your body burns at rest — using the Mifflin–St Jeor equation:
- Men: 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5
- Women: 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161
It then multiplies your BMR by an activity factor (1.2 for sedentary up to 1.9 for extra active) to get your Total Daily Energy Expenditure (TDEE) — the calories needed to maintain your current weight.
To lose or gain weight, you adjust intake from there. Since roughly 7,700 calories equals one kilogram (about 3,500 per pound) of body fat, a 500-calorie daily deficit works out to about half a kilogram, or one pound, per week.
Common calorie questions
How many calories do I need a day? It depends on your age, sex, height, weight, and activity. Enter them above and the calculator shows your maintenance number.
What is TDEE? Total Daily Energy Expenditure — all the calories you burn in a day. Eat around it to stay the same weight, less to lose, more to gain.
How many calories to lose weight? About 500 fewer than your TDEE each day gives roughly half a kilogram (one pound) of loss per week. The table above shows gentler and faster options too.
Which formula does this use? The Mifflin–St Jeor equation, which dietitians widely recommend for healthy adults.
Is it safe to eat very few calories? Very low intakes can be unsafe. Many guidelines advise staying above about 1,200 calories a day for women and 1,500 for men without medical supervision.
This calculator is for general information only and is not medical or nutritional advice. Talk to your doctor or a registered dietitian before making big changes to how you eat.