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TDEE Calculator

Mifflin-St Jeor estimates resting energy expenditure from weight, height, age and sex — a published regression on 498 people whose expenditure was measured by indirect calorimetry. An activity factor turns that into a daily total; the factor is a widely used convention rather than part of the paper, and the result says which figure is which. It sets no target, deficit or surplus.

Last reviewed: September 21, 2026

Mifflin-St Jeor estimates resting energy expenditure from weight, height, age and sex. An activity factor turns that into a daily total.

The 1990 regression was fitted with a two-level sex term and produces two equations. This field selects which of the published equations to use; it is not a statement about anything else.

How the calculation works

Mifflin, St Jeor and colleagues published a regression equation for resting energy expenditure from weight, height, age and sex, fitted against 498 healthy subjects whose actual expenditure was measured by indirect calorimetry (R² = 0.71):

  • Resting expenditure (male) = 10 × weight (kg) + 6.25 × height (cm) − 5 × age (years) + 5
  • Resting expenditure (female) = 10 × weight (kg) + 6.25 × height (cm) − 5 × age (years) − 161

The activity multiplier is convention, not part of this equation. Turning a resting figure into a daily total multiplies it by an activity factor (1.2 for sedentary, up to 1.9 for extra active). That ladder does not appear in the 1990 paper — which is a resting-expenditure equation only, with no activity term — and carries no primary citation Prof. Peptide has read. It is a widely repeated convention, included because a TDEE tool without one answers a narrower question than the one asked, but it is not presented as equally established.

Worked examples

An 80 kg, 180 cm, 30-year-old man, at a moderate activity factor (×1.55):

Resting expenditure10(80) + 6.25(180) − 5(30) + 5 = 1780 kcal/day
Daily total, convention1780 × 1.55 = 2759 kcal/day

A 65 kg, 165 cm, 28-year-old woman, at a sedentary activity factor (×1.2):

Resting expenditure10(65) + 6.25(165) − 5(28) − 161 = 1380 kcal/day
Daily total, convention1380 × 1.2 = 1656 kcal/day

Enter either set of numbers into the calculator above and it returns the same figures. No deficit, surplus or target is set anywhere on this page.

FAQ

What is my resting energy expenditure?
Mifflin-St Jeor (1990) gives it from weight, height, age and sex: 10 × weight (kg) + 6.25 × height (cm) − 5 × age (years), + 5 for the equation's male term or − 161 for its female term. An 80 kg, 180 cm, 30-year-old man comes to 1780 kcal/day by this equation.
tdee calculator mifflin st jeor
This page's calculator applies the Mifflin-St Jeor equation to your weight, height, age and sex for a resting energy expenditure figure, then optionally multiplies it by an activity factor for a daily total. The resting figure is cited to its 1990 source; the activity factor is labelled as a convention with no citation, since the source paper contains no activity term.
Is the activity multiplier scientifically validated?
The 1.2 to 1.9 activity-factor ladder is a widely repeated convention in fitness and nutrition writing, not a figure from the Mifflin-St Jeor paper or any other primary source Prof. Peptide has read. The 1990 paper is a resting-expenditure equation only and contains no activity term at all. This page states that distinction rather than presenting the multiplied total as equally established.
What's the difference between BMR and TDEE?
BMR (basal metabolic rate) and resting energy expenditure are closely related measures of energy burned at rest; this page calculates resting energy expenditure by the Mifflin-St Jeor equation. TDEE (total daily energy expenditure) is that resting figure multiplied by an activity factor to account for movement and exercise — the multiplier this page labels as convention rather than as part of the cited equation.

References

  1. Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr. 1990 Feb;51(2):241-7. https://pubmed.ncbi.nlm.nih.gov/2305711/
  2. The activity-factor ladder (1.2–1.9) is a widely repeated convention, not drawn from the paper above or any other primary source this page cites.