Estimate daily calorie needs for maintenance, fat loss, or weight gain using the Mifflin-St Jeor BMR equation and an activity multiplier.
TDEE = BMR × activity multiplierThis calorie calculator uses the Mifflin-St Jeor equation to estimate BMR, then multiplies it by an activity factor to estimate total daily energy expenditure. A smaller calorie deficit supports gradual fat loss; a controlled surplus supports weight gain.
| Symbol | Variable | Description |
|---|---|---|
| BMR | Basal metabolic rate | Calories your body uses at rest before exercise and daily movement. |
| TDEE | Total daily energy expenditure | Estimated maintenance calories after activity is included. |
| activity | Activity multiplier | A practical estimate of exercise, job demands, and normal daily movement. |
Enter your profile
Add age, sex, height, and weight. These values drive the BMR estimate.
Choose activity level
Pick the activity option that best matches a normal week, not your hardest day.
Read the calorie targets
Use maintenance calories for weight stability, a deficit for fat loss, or a small surplus for lean weight gain.
Choose the result that matches your goal. Maintenance calories are the best starting point if you want to keep weight stable or learn your baseline. For fat loss, a 250 to 500 kcal deficit is usually easier to sustain than an aggressive cut. For weight gain, start with a small surplus and monitor scale trend, training performance, and appetite.
The biggest source of error in a daily calorie calculator is usually activity level. A desk job with a few walks is not the same as a physical job, even if both people train three times per week.
Use the calorie estimate as a starting point, then validate it with real data. Weigh yourself under similar conditions several times per week and compare weekly averages. If weight is not moving toward your goal after 2 to 4 weeks, adjust intake modestly rather than making a large swing.