To calculate TDEE by hand, work out your BMR with the Mifflin-St Jeor equation, then multiply it by your activity factor. For a 30-year-old man who weighs 80 kg, is 178 cm tall and exercises 3–5 days a week, that gives a BMR of 1,768 calories and a TDEE of about 2,740. Want the answer without the arithmetic? The TDEE calculator does it instantly and compares three formulas.
What you need
- Your weight in kilograms (pounds ÷ 2.2046)
- Your height in centimetres (inches × 2.54)
- Your age in years
- Your activity level, from the table below
Step 1: Calculate BMR with Mifflin-St Jeor
6.25 × 178 = 1,112.5
5 × 30 = 150
800 + 1,112.5 − 150 + 5 = 1,767.5, so BMR ≈ 1,768 calories a day.
Step 2: Multiply by your activity factor
| Activity level | Factor | TDEE in the example |
|---|---|---|
| Sedentary: desk job, little exercise | 1.2 | 2,121 |
| Light: exercise 1–3 days a week | 1.375 | 2,430 |
| Moderate: exercise 3–5 days a week | 1.55 | 2,740 |
| Very active: hard exercise 6–7 days | 1.725 | 3,049 |
| Athlete: twice-a-day training | 1.9 | 3,358 |
Our man trains four days a week, so he uses 1.55: 1,767.5 × 1.55 = 2,739.6, or about 2,740 calories a day. If you are not sure which level fits, read how to choose your activity level honestly.
Step 3: Set your goal
TDEE is your maintenance. Subtract 250–500 calories to lose weight, or add 250–500 to gain. For our example, a 500-calorie deficit gives 2,240 a day. How big should your calorie deficit be? helps you pick the size.
The other two formulas
Revised Harris-Benedict
For the same man: 88.362 + 1,071.76 + 854.22 − 170.31 = 1,844 calories. × 1.55 = 2,858, about 118 more than Mifflin-St Jeor.
Katch-McArdle (needs body fat)
At 18% body fat his lean mass is 80 × 0.82 = 65.6 kg. BMR = 370 + 21.6 × 65.6 = 1,787. × 1.55 = 2,770. No body fat number? Estimate it with the body fat calculator.
Three formulas, three answers within about 120 calories of each other. That spread is normal. Which TDEE formula should you use? explains when each one is the better fit.
Check your answer
Enter the same numbers in the TDEE calculator. You should land within a few calories, with any difference down to rounding. Then treat the result as a starting point: eat it for 2–3 weeks and see what your scale does. How to find your real maintenance calories shows how.
Skip the arithmetic and compare all three formulas.
Open the TDEE calculatorFrequently asked questions
Can I calculate TDEE without a calculator?
How do I convert pounds and inches?
Why does my hand calculation differ slightly from the calculator?
Which activity factor should I use?
Keep reading
Sources
- 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;51(2):241–247. PubMed 2305711
- Roza AM, Shizgal HM. The Harris Benedict equation reevaluated: resting energy requirements and the body cell mass. Am J Clin Nutr. 1984;40(1):168–182. PubMed 6741850
- Frankenfield D, Roth-Yousey L, Compher C. Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults: a systematic review. J Am Diet Assoc. 2005;105(5):775–789. PubMed 15883556