In short
- TDEE is an estimate, not a fixed personal measurement.
- Estimate BMR first, then apply an activity multiplier.
- Compare the result with several weeks of real-world trends before adjusting it.
What TDEE means
Total daily energy expenditure (TDEE) is an estimate of how much energy your body uses across an average day. It combines resting energy with movement, training and the energy used to digest food. Because daily activity varies, TDEE is best treated as a starting range rather than a fixed personal constant.
Step 1: estimate resting energy
CalcQuick uses the Mifflin–St Jeor equation. It combines weight in kilograms, height in centimeters and age, with a sex-specific constant. The answer is basal metabolic rate (BMR): an estimate of energy use at rest.
Step 2: choose an activity multiplier
Multiply BMR by an activity factor. A sedentary estimate often uses 1.2; light activity 1.375; moderate activity 1.55; and very active routines 1.725. Choose based on the pattern of a normal week, not the hardest day.
- Sedentary: little structured exercise
- Light: about 1–3 active sessions each week
- Moderate: about 3–5 active sessions
- Very active: hard training most days
Use the estimate as a baseline
Compare the estimate with several weeks of body-weight and energy trends. Sleep, illness, medication, pregnancy and individual metabolism can change needs. A clinician or registered dietitian can help when the number affects a medical or nutrition plan.
Sources
These primary or official references support the formulas, definitions or scope used in this guide.