How your calories are calculated
This tool uses the Mifflin-St Jeor equation, the formula most dietitians consider the most accurate for estimating calorie needs. First it finds your BMR — the calories your body burns at complete rest — then multiplies it by an activity factor to get your TDEE (Total Daily Energy Expenditure), the calories you burn in a normal day.
Men: BMR = 10·kg + 6.25·cm − 5·age + 5
Women: BMR = 10·kg + 6.25·cm − 5·age − 161
Losing or gaining weight
Roughly 7,700 calories equals one kilogram of body fat. Eating about 500 fewer calories a day than your TDEE loses about 0.5 kg per week; 250 fewer loses about 0.25 kg. Gaining works the same way in reverse. Very aggressive deficits are hard to sustain and can cost muscle — slow and steady wins.
What are macros?
Your calories come from three macronutrients: protein, carbohydrates (4 calories per gram each) and fat (9 calories per gram). The split above (30/40/30) is a balanced starting point — active people and those building muscle often raise protein. Adjust to what keeps you full and consistent.
These are estimates for general information, not medical or dietary advice. Individual needs vary — consult a doctor or dietitian before making big changes, especially if you have a health condition.