Calorie Calculator
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Enter your age, sex, height, weight and activity level to estimate your BMR and daily maintenance calories (TDEE), along with targets for gradual weight loss or gain. Everything is calculated on your device.
How your calorie needs are calculated
This calculator works in two stages. First it estimates your Basal Metabolic Rate (BMR) using the Mifflin-St Jeor equation, which is widely regarded as one of the most accurate predictive formulas for healthy adults. BMR is the energy your body burns at complete rest just to keep organs, breathing and temperature running.
The equation is 10 x weight(kg) + 6.25 x height(cm) - 5 x age(years), then +5 for males or -161 for females. Your BMR is then multiplied by an activity factor to give your Total Daily Energy Expenditure (TDEE), the number of calories that keeps your weight stable given how much you move.
Choosing the right activity level
The activity multiplier has a large effect, so it is worth being honest rather than optimistic. Sedentary (1.2) suits a desk job with little exercise; light (1.375) is one to three workouts a week; moderate (1.55) is three to five; active (1.725) is six to seven; and very active (1.9) fits hard daily training or a physically demanding job.
If you are unsure, start one level lower than you think and adjust after a couple of weeks based on real results. Estimates from any formula are a starting point, not a measured value, so your own weight trend is the ultimate feedback.
Turning calories into a goal
Maintenance calories hold your weight steady. To lose weight you eat below that number, and to gain you eat above it. A deficit or surplus of roughly 250 kcal per day corresponds to about 0.25 kg per week, and 500 kcal to about 0.5 kg per week, because a kilogram of body fat stores roughly 7,700 kcal.
Slower changes are usually easier to sustain and protect muscle better than aggressive dieting. The targets shown here are practical guides for planning meals; they are not medical or nutritional advice, and very low intakes should be discussed with a professional.
Frequently asked questions
What is the difference between BMR and TDEE?
BMR is the energy you burn at complete rest. TDEE is BMR multiplied by an activity factor, so it includes movement, exercise and daily living, and is the number that actually reflects your maintenance calories.
Why does age lower my calorie needs?
Metabolic rate tends to decline gradually with age as muscle mass and cellular activity change, so the formula subtracts a small amount per year to reflect that trend.
Should men and women use different numbers?
Yes. The formula adds 5 for males and subtracts 161 for females, mainly to account for average differences in lean body mass between the sexes.
How accurate is the estimate?
Predictive formulas are usually within about 10 percent for most healthy adults, but individual metabolism varies. Track your weight for two to three weeks and adjust intake based on the real trend.
Can I use this to gain muscle?
Yes. Eat slightly above your maintenance number, often 250 to 500 kcal, combine it with resistance training and adequate protein, and adjust based on how your weight and strength progress.
Is my information stored anywhere?
No. The calculation runs entirely in your browser using basic arithmetic, so your age, height and weight are never uploaded or saved.
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