FitCalc

How to Calculate Your TDEE

Your TDEE is the calorie intake at which your weight stays stable, and it is the base for any diet or bulk. This guide shows how to calculate it and, more importantly, how to check the answer.

Quick answer: TDEE = BMR × activity factor, where the factor runs from 1.2 (sedentary) to 1.9 (very active). A BMR of 1,700 kcal at the moderate 1.55 factor gives a TDEE of about 2,635 kcal. Verify it by eating a fixed amount for 2–3 weeks and watching your weight.

Step one: estimate BMR

Use Mifflin-St Jeor, the most accurate general-purpose equation, or Katch-McArdle if you know your body fat percentage. BMR is the base that the activity factor multiplies.

Step two: pick the activity factor

The multipliers are 1.2 sedentary, 1.375 light (1–3 sessions a week), 1.55 moderate (3–5), 1.725 very active (6–7) and 1.9 extra active (hard training plus physical work). Be conservative — most people overestimate their activity, and the factor is the largest source of error.

Step three: verify with real data

The formula gives an estimate; your scale gives the answer. Eat a consistent calorie amount for two to three weeks. Stable weight means that intake is your TDEE. Gaining or losing tells you to move the number by the implied amount, around 100–200 kcal per 0.5 lb per week of error.

Why the estimate drifts

TDEE falls as you lose weight, drops with age, and rises with activity and muscle. It also fluctuates day to day with training and non-exercise movement. Recalculate after every 4–6 kg of change or any significant shift in routine.

Using TDEE for a goal

Cut at 15–20% below TDEE for fat loss, bulk at 10–15% above for muscle gain, and eat at TDEE to maintain. A diet break, eating at maintenance for a week or two during a long diet, can restore adherence and ease fatigue.

Frequently Asked Questions

How do I calculate TDEE?
Multiply your BMR by an activity factor between 1.2 and 1.9. The TDEE calculator does this and returns maintenance plus loss and gain targets.
How accurate is TDEE?
Within roughly 10–15% for an individual, mostly because self-reported activity is imprecise. Two to three weeks of real weight data beats any formula.
Why is my TDEE lower than calculated?
Usually because the activity factor is set too high, or because metabolic adaptation has lowered expenditure during a long diet. Recalculate and trust the scale.
Does TDEE include exercise?
Yes, through the activity multiplier. If you log individual workouts separately, pick a lower activity band so you do not count them twice.

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