Calorie Calculator
Enter your details to see how many calories you burn per day and what to eat to lose or gain weight.
Fill in your age, height, and weight to see your calorie needs.
Based on the Mifflin-St Jeor equation. Processed on your device — nothing is sent anywhere.
How it works
- Select your sex and enter your age, height, and weight.
- Pick the activity level that best matches a typical week.
- Read your BMR, maintenance calories, and daily targets below.
Frequently asked questions
- How are the calories calculated?
- The tool uses the Mifflin-St Jeor equation, which estimates your basal metabolic rate from sex, age, height, and weight. That number is then multiplied by an activity factor between 1.2 and 1.9 to estimate your total daily energy expenditure, also called maintenance calories.
- What is the difference between BMR and maintenance calories?
- BMR is the energy your body burns at complete rest just to keep basic functions running. Maintenance calories add the energy you spend moving around, working, and exercising. Eating at maintenance keeps your weight stable over time.
- How do the weight loss and gain targets work?
- A deficit of roughly 500 calories per day corresponds to losing about 0.5 kg (1 lb) per week, and a 250-calorie deficit to about half that pace. The gain targets add the same amounts instead. These are estimates — adjust based on how your weight actually changes over a few weeks.
- Which activity level should I choose?
- Most people overestimate. Choose sedentary if you have a desk job and little formal exercise, light for one to three workouts a week, and moderate for three to five. The active levels are for physically demanding jobs or near-daily training. If you are unsure, pick the lower level and adjust after two or three weeks of tracking your weight.
- Is my personal data stored or sent to a server?
- No. Age, height, weight, and every result are computed locally in your browser with no network requests, so nothing is uploaded, logged, or saved. You can even use the calculator offline once the page has loaded.
About this tool
This calorie calculator estimates how much energy your body uses per day and turns it into practical eating targets. From your sex, age, height, weight, and activity level it computes your basal metabolic rate, your maintenance calories, and a set of daily intakes for losing or gaining weight at a moderate or faster pace. Results appear instantly and update as you change any input.
The estimate is based on the Mifflin-St Jeor equation, which studies have found to be the most accurate of the common BMR formulas for the general population, outperforming the older Harris-Benedict equation. BMR — the energy burned at complete rest — is multiplied by an activity factor from 1.2 (sedentary) to 1.9 (very active) to produce total daily energy expenditure. The loss and gain targets then apply the standard rule of thumb that a 500-calorie daily deficit yields roughly half a kilogram, about one pound, of weight change per week.
Everything is computed client-side in your browser. Body measurements are sensitive data, and this calculator sends none of it anywhere: there are no network requests, no stored profiles, and no account. Enter your numbers, read the results, close the tab — nothing persists.
Treat the output as a calibrated starting point rather than a prescription. Formulas estimate the average person of your stats, but individual metabolisms vary by a few hundred calories either way, and self-selected activity levels are the biggest source of error — when in doubt, choose the lower one. The reliable method is to eat at the suggested target for two to three weeks, weigh yourself under consistent conditions, and adjust by 100–200 calories based on the actual trend. Losing much faster than about 1% of body weight per week tends to cost muscle, so the moderate targets are the sensible default for most people.