Health
Calorie & TDEE Calculator
TDEE is a resting figure multiplied by an activity guess. The first comes from a laboratory, the second is a convention — this page keeps them apart instead of blending them into one number.
The link carries your figures, so it reopens on exactly these numbers.
The formula
Worked example
A 35-year-old man, 175 cm, 74 kg, moderately active
- 10 × 74 = 740
- 6.25 × 175 = 1,093.75
- 740 + 1,093.75 − 175 + 5 = 1,663.75 kcal at rest
- 1,664 × 1.55 = 2,579 kcal a day
Where this goes wrong
Treating a regression on 498 people as your own metabolism
Mifflin–St Jeor was fitted to 498 healthy adults and reports R² = 0.71 — it explains 71% of the variation between individuals, which means close to a third of it is something else entirely. For a resting figure near 1,664 kcal, the honest spread is roughly ±250 kcal before the activity multiplier is even applied, and that multiplier is a convention with no comparable evidence behind it. The output is a starting estimate to adjust against what actually happens to your weight over a few weeks, not a budget to obey to the kilocalorie.
Questions
- What is TDEE?
- Total daily energy expenditure — everything you burn in a day, not just at rest. It is calculated here the way it is calculated everywhere: a resting metabolic rate from the Mifflin–St Jeor equation, multiplied by an activity factor. What differs is that this page shows you the two parts rather than the product alone, because they are not equally trustworthy.
- What is BMR and how is it different from TDEE?
- Basal or resting metabolic rate is what your body uses doing nothing at all — breathing, circulating, maintaining temperature. TDEE is that figure multiplied by an activity factor to cover everything you do awake. The first is measured science; the second is an educated convention, which is why this page shows them as separate numbers. If you only want the resting figure and the margin it carries, the BMR calculator does that on its own.
- Why is the activity multiplier the weakest part?
- Because it is the only part with no laboratory behind it. The equation was fitted to 498 people measured by indirect calorimetry; the multipliers (1.2 sedentary, 1.55 moderate, 1.9 very hard) are a convention that circulated into general use without a comparable validation study. On a typical entry the multiplier contributes more than a third of the total — the least sourced number is the largest one on the page.
- Which equation does this use, and why?
- Mifflin–St Jeor, published in the American Journal of Clinical Nutrition in 1990 from indirect calorimetry on 498 healthy adults. It replaced the older Harris–Benedict equation, derived in 1919 from a much smaller and less representative sample, and it remains the best-validated predictor for healthy adults.
- Why does the equation only offer two options for sex?
- Because that is what the 1990 study measured: it fitted two constants, +5 and −161, to male and female subjects. This page reports the equation as published rather than extrapolating beyond its data. If neither constant describes you, the honest reading is that this equation was not derived for your case.
- How accurate is it for me personally?
- Approximately, and the page tells you how approximately. R² = 0.71 means the four inputs account for about 71% of the differences between people; body composition, thyroid function, genetics and measurement error account for the rest. Use it as a starting point and correct it against your own results.