Calculate your daily calorie needs based on age, weight, height, and activity level using the Mifflin-St Jeor equation.
Calories are units of energy that your body uses to function — from breathing and digestion to exercise and thinking. Understanding your daily calorie needs is the foundation of any diet or fitness plan. This calculator first estimates your Basal Metabolic Rate (BMR) — the calories burned at complete rest using the Mifflin-St Jeor equation, the most accurate formula for most adults. It then multiplies by an activity factor to get your Total Daily Energy Expenditure (TDEE). To lose weight, eat below TDEE (typically -500 kcal/day = ~0.5kg/week loss); to gain muscle, eat slightly above TDEE (+200–300 kcal/day). The goal is understanding your baseline, not obsessing over every calorie.
BMR (Basal Metabolic Rate) is the calories you'd burn lying still all day. TDEE (Total Daily Energy Expenditure) adds your actual activity level. TDEE is what you should base your food intake on.
The Mifflin-St Jeor formula is accurate to within 10% for most adults. Individual metabolism varies based on genetics, muscle mass, hormones, and gut microbiome. Treat this as a starting point, then adjust based on real results.
A 500-calorie daily deficit typically results in about 0.5kg (1 lb) of fat loss per week. Avoid cutting more than 1000 kcal/day as it can cause muscle loss and metabolic adaptation.
If you selected your correct activity level, exercise is already factored into your TDEE. Don't double-count by also adding exercise calories on top.
Not necessarily. Many people naturally eat more on active days and less on rest days. Hitting your weekly calorie target matters more than hitting it perfectly every single day.