Daily Calorie Calculator

Calculate your estimated daily calorie needs free online using the Mifflin-St Jeor equation, the most accurate widely-used formula for resting metabolic rate estimation.

Age

Height (cm)

Weight (kg)

Sex

Activity Level

Browser only. Estimate only -- individual metabolism varies.

How to Use This Tool

Enter age, height, and weightYour current measurements

Select sex and activity levelBe realistic about actual activity

See BMR and total daily caloriesMaintenance estimate at your current weight

Mifflin-St Jeor -- The Formula Dietitians Currently Recommend

Several formulas exist for estimating resting metabolic rate, but research comparing their accuracy has generally found Mifflin-St Jeor performs better than older alternatives like Harris-Benedict for most people, which is why it's become the more commonly recommended starting point among registered dietitians today.

BMR Is Just the Starting Point

Basal Metabolic Rate represents energy needed at complete rest -- a baseline, not your actual daily need. Multiplying by an activity factor accounts for movement and exercise, and this multiplier can nearly double the final number between a sedentary lifestyle and very intense regular activity, making honest activity assessment more impactful than precision elsewhere in the calculation.

A Population Estimate, Not an Individual Measurement

This formula works from height, weight, age, and sex -- it cannot capture individual variation in muscle mass, genetics, or metabolic health that affects real individual metabolism. Use the result as a reasonable starting point to test against real observed results (weight trend over several weeks) rather than treating it as a precise individual number.

Frequently Asked Questions

Research comparing common BMR formulas has found Mifflin-St Jeor to be generally more accurate than older formulas like Harris-Benedict for most people, which is why it's the formula many registered dietitians and the Academy of Nutrition and Dietetics currently recommend as a starting point.

BMR (Basal Metabolic Rate) is the energy your body needs at complete rest just to maintain basic functions. Total daily calorie needs multiply BMR by an activity factor to account for movement and exercise throughout the day, since BMR alone underrepresents real-world energy expenditure.

Population-based formulas like this provide a reasonable starting estimate, but actual individual metabolism varies due to genetics, muscle mass, and other factors not captured by height, weight, age, and sex alone. Treat the result as a starting point to adjust based on real observed results over time, not a precise individual measurement.

Activity level can roughly double total calorie needs between a sedentary lifestyle and very intense regular exercise, which is why honestly assessing your real activity level matters far more for an accurate estimate than precision in the underlying BMR calculation.

This estimates maintenance calories at current weight. Adjusting from there for weight loss or gain involves a separate decision about calorie deficit or surplus size, which involves additional considerations beyond just this baseline number.