Calorie Calculator
Estimate your daily calorie needs using the Mifflin-St Jeor equation, adjusted for activity level and goal.
How this is calculated
This tool uses the Mifflin-St Jeor equation — widely regarded as the most accurate resting metabolic rate formula for most adults — to estimate your Basal Metabolic Rate (BMR), then multiplies it by an activity factor to get your Total Daily Energy Expenditure (TDEE), your maintenance calories. Your goal then adds or subtracts a calorie deficit/surplus (roughly 3,500 kcal ≈ 1 lb / 0.45 kg of body weight per week).
The macro split shown (30% protein / 40% carbs / 30% fat) is a reasonable general-purpose starting point, not a prescription — individual needs vary.
This is an estimate for healthy adults and isn't medical advice. It doesn't account for medical conditions, pregnancy, or highly individual metabolic factors — talk to a doctor or dietitian before starting any calorie-restricted diet.
Sources: Resting metabolic rate is calculated with the Mifflin-St Jeor equation (Mifflin MD, St Jeor ST et al., “A new predictive equation for resting energy expenditure in healthy individuals,” American Journal of Clinical Nutrition, 1990), the formula most commonly recommended for healthy adults. Activity multipliers run from 1.2 (sedentary) to 1.9 (very active), the standard factors used to convert BMR into total daily energy expenditure. The 3,500 kcal ≈ 1 lb (0.45 kg) figure is a conventional energy-balance rule of thumb, not an exact physiological constant. The 30/40/30 macro split shown here is a general-purpose starting point; for reference, the Institute of Medicine’s Acceptable Macronutrient Distribution Ranges are 10–35% protein, 45–65% carbohydrate and 20–35% fat.