How many calories does your body actually need?

What formula does this use?

BMR is calculated with the Mifflin-St Jeor equation, generally considered more accurate than the older Harris-Benedict formula. TDEE (Total Daily Energy Expenditure) multiplies BMR by an activity factor to estimate total calories burned per day.

How are the weight loss and gain targets calculated?

Weight loss target subtracts 500 calories from TDEE, and weight gain target adds 500 — a 500-calorie daily deficit or surplus roughly corresponds to about 0.5kg (1lb) of change per week, a commonly used moderate pace.

Is this accurate for everyone?

These are population-average formulas — actual metabolism varies with muscle mass, genetics, and health conditions. Treat the numbers as a reasonable starting point, not a precise measurement, and adjust based on how your actual weight responds over a few weeks.

How accurate is this compared to a lab measurement?

The Mifflin-St Jeor formula is a population-average estimate validated against measured metabolic rates, generally accurate within about 10% for most people — but true metabolism varies with genetics, muscle mass, and health conditions, so a DEXA scan or metabolic cart test would be more precise for any individual.

Should I eat exactly my TDEE every day?

TDEE is a maintenance estimate, not a daily target — actual intake naturally varies day to day, and what matters for weight management is the average over a week or two, not hitting an exact number every single day.

Worked example: a 30-year-old male, 75kg, 178cm, moderately active: BMR = 10×75 + 6.25×178 − 5×30 + 5 = 750+1112.5−150+5 = 1,717.5 kcal. TDEE = 1,717.5 × 1.55 ≈ 2,662 kcal/day for maintenance.