Calorie Calculator

This calculator uses the Mifflin-St Jeor equation to calculate Basal Metabolic Rate (BMR), which is then multiplied by an activity factor to estimate Total Daily Energy Expenditure (TDEE). The Mifflin-St Jeor equation is the most commonly recommended formula by registered dietitians and is considered more accurate than the older Harris-Benedict equation for most adults.

BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest to maintain basic functions such as breathing, circulation, and cell production. TDEE (Total Daily Energy Expenditure) adds your activity level on top of BMR to estimate total calories burned in a day. TDEE is the number you should compare to your food intake to determine if you are in a calorie surplus, deficit, or at maintenance.

A common guideline is to consume 500 fewer calories per day than your TDEE to lose approximately one pound per week, since one pound of fat stores roughly 3,500 calories. Deficits larger than 1,000 calories per day are generally not recommended without medical supervision because they can cause muscle loss, nutrient deficiencies, and metabolic adaptation. Consult a registered dietitian for a personalized plan.

Sedentary applies to people with desk jobs who do little to no exercise. Lightly Active covers light exercise one to three days per week. Moderately Active means moderate exercise three to five days per week. Very Active covers hard exercise six to seven days per week. Extra Active applies to people with physically demanding jobs or who exercise twice a day.

The Mifflin-St Jeor equation has been validated in numerous clinical studies and is accurate within roughly 10 percent for most healthy adults. However, individual metabolic rates vary due to factors including muscle mass, hormones, medications, and genetics. The estimates here are a starting point. Track your actual intake and weight over two to four weeks to calibrate your real maintenance level.