InstaCalcs

Calorie Calculator

Estimate how many calories you need per day to maintain, lose, or gain weight. Uses the Mifflin-St Jeor equation — widely considered the most accurate formula for calculating resting metabolic rate.

How to Use

Enter your age, select your gender, input your height and weight, and choose your activity level from sedentary to extra active. The calculator determines your Basal Metabolic Rate (BMR) and multiplies it by your activity factor to estimate daily calories for maintenance. It also shows targets for mild weight loss (-250 cal), weight loss (-500 cal), and weight gain (+500 cal).

Mifflin-St Jeor Formula

Men: BMR = 10 × weight(kg) + 6.25 × height(cm) - 5 × age - 161 + 166

Women: BMR = 10 × weight(kg) + 6.25 × height(cm) - 5 × age - 161

The BMR is then multiplied by an activity factor: Sedentary (×1.2), Lightly Active (×1.375), Moderately Active (×1.55), Very Active (×1.725), or Extra Active (×1.9). This gives your Total Daily Energy Expenditure (TDEE), the number of calories you burn per day.