What Is TDEE? Meaning, Formula & Calculation

What makes up your daily energy use?

Resting energy keeps basic functions running. Non-exercise activity includes walking around the house, standing and physical work. Exercise adds deliberate training. Digesting and processing food also uses energy, called the thermic effect of food. Their relative contributions vary; the same person can have different needs on different days.

A calculator cannot measure these four parts separately. TDEE Calculator estimates resting energy and multiplies it by an activity factor that represents the whole day. The movement allowance in the result is a modelled difference, not the calories from one workout.

How to calculate TDEE: a worked example

The starting rule is TDEE ≈ resting energy × activity factor. Without body-fat data, automatic mode uses Mifflin–St Jeor. For a 30-year-old woman at 65 kg and 168 cm:

10 × 65 + 6.25 × 168 − 5 × 30 − 161 = 1,389 kcal/day

Choosing the light activity factor, 1.375, gives 1,389 × 1.375 = 1,910 kcal/day after rounding. This is an example, not a recommendation for someone with those measurements. Different activity assumptions change the answer. Enter your own details in the TDEE calculator.

Maintenance, a calorie goal and observed needs

Maintenance means intake that roughly balances expenditure over time. For a loss goal, a planned deficit is taken from maintenance; for gain, a surplus is added. Do not subtract a deficit from resting calories instead. Our calorie deficit tool shows 10%, 15% and 20% planning options and low-intake cautions.

Use a calculator as a starting hypothesis. Keep your routine reasonably consistent and compare several weeks of weight and intake, rather than changing food after every scale fluctuation. The local weight and calorie journal can estimate observed needs after 21 complete consecutive days. Water changes and logging error still matter.

Who needs a different approach?

These tools are for generally healthy adults aged 18–100. Children, pregnancy, breastfeeding, illness, medication changes and an eating-disorder history need an approach suited to the situation. A prediction is not a measurement, and no single number proves that an intake is adequate. Discuss individual concerns with a qualified clinician or dietitian.