About you

yrs
lb
in

Daily calorie target

kcal

How this works

Methodology reviewed July 2026

This tool estimates the calories you burn in a day (your Total Daily Energy Expenditure) using the Mifflin-St Jeor equation for resting metabolic rate, scaled by an activity factor. It then splits a goal-adjusted calorie target into protein, fat, and carbohydrate — protein set high enough to protect lean mass while you lose fat.

FormulaBMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + s s = +5 (male), −161 (female) TDEE = BMR × activity factor (1.2 sedentary … 1.725 very active) Goal calories = TDEE ± deficit/surplus
Inputs

Sex · Age · Height · Weight · Activity level · Goal

Outputs

Maintenance calories (TDEE) · Goal calorie target · Protein / fat / carb grams

Assumptions
  • Mifflin-St Jeor estimates an average person's RMR; individuals vary ±10% or more.
  • Activity multipliers are broad self-report bands, not measured expenditure.
Limitations
  • TDEE is an estimate, not a measurement — use it as a starting point and adjust from real-world weight change over 2–3 weeks.
  • It does not model metabolic adaptation during a prolonged deficit.
Safety
  • Very low calorie targets can be unsafe; this tool is educational, not a prescription.

This calculator is for educational purposes only and is not medical advice, diagnosis, or treatment. Results are estimates based on published formulas and population averages — your individual values may differ. Nothing here is calculated on a server: everything runs in your browser and no data is stored or sent anywhere. Always consult a qualified clinician before making health, medication, or training decisions.