What TDEE means
Your total daily energy expenditure (TDEE) is every calorie your body uses in a day. It has four parts:
- Basal metabolic rate (BMR), the energy to keep you alive at rest: breathing, circulation, brain and organs. For most people this is the biggest share, often around 60–70% of the total.
- The thermic effect of food, the energy used to digest and absorb what you eat, roughly 10% of intake.
- Exercise, the training you do on purpose.
- Non-exercise activity (NEAT): walking, standing, fidgeting, housework. This varies widely between people and is often what separates a “fast” from a “slow” metabolism.
You cannot measure TDEE easily at home, so calculators estimate it from your BMR and an activity factor.
How the TDEE calculator works
First the calculator estimates your BMR. With no body fat entered it uses the Mifflin-St Jeor equation (American Journal of Clinical Nutrition, 1990), the equation an American Dietetic Association review found most likely to land within 10% of measured resting energy expenditure in healthy adults (Frankenfield et al., 2005):
Men: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5 Women: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161
If you know your body fat percentage, it uses the Katch-McArdle equation instead, which is based on lean body mass and ignores sex and age:
BMR = 370 + 21.6 × lean body mass (kg) lean body mass = weight × (1 − body fat % ÷ 100)
Then BMR is multiplied by the activity factor you choose:
TDEE = BMR × activity factor 1.2 sedentary · 1.375 lightly active · 1.55 moderately active · 1.725 very active · 1.9 extra active
Worked example
A 40-year-old man, 183 cm (6 ft 0 in) and 90 kg (198 lb), with an office job who exercises twice a week:
- BMR = 10 × 90 + 6.25 × 183 − 5 × 40 + 5 = 1,849 kcal
- TDEE (lightly active) = 1,849 × 1.375 = 2,542 kcal a day
If he measures his body fat at 25%, his lean mass is 67.5 kg, so Katch-McArdle gives BMR = 370 + 21.6 × 67.5 = 1,828 kcal and a TDEE of about 2,514 kcal. The two equations agree within about 30 kcal here. They drift further apart for people who are very lean and muscular or who carry a lot of body fat.
TDEE at each activity level
Calories a day for the man in the example above:
| Activity level | Typical week | Factor | TDEE (kcal a day) |
|---|---|---|---|
| Basal (BMR) | Complete rest | 1.0 | 1,849 |
| Sedentary | Desk job, little or no exercise | 1.2 | 2,219 |
| Lightly active | Light exercise 1-3 days a week | 1.375 | 2,542 |
| Moderately active | Moderate exercise 3-5 days a week | 1.55 | 2,866 |
| Very active | Hard exercise 6-7 days a week | 1.725 | 3,189 |
| Extra active | Physical job plus hard training | 1.9 | 3,513 |
Man, 40 years, 183 cm (6 ft 0 in), 90 kg (198 lb), Mifflin-St Jeor.
Maintenance calories by body weight
Calories a day for a 35-year-old woman who is 165 cm (5 ft 5 in) tall, at three activity levels. Every 10 lb (4.5 kg) of body weight changes TDEE by about 55–80 kcal a day, depending on activity.
| Weight | Sedentary | Moderate | Very active |
|---|---|---|---|
| 130 lb (59 kg) | 1,542 | 1,992 | 2,216 |
| 150 lb (68 kg) | 1,651 | 2,132 | 2,373 |
| 170 lb (77 kg) | 1,760 | 2,273 | 2,529 |
| 190 lb (86 kg) | 1,868 | 2,413 | 2,686 |
| 210 lb (95 kg) | 1,977 | 2,554 | 2,842 |
| 230 lb (104 kg) | 2,086 | 2,695 | 2,999 |
Woman, 35 years, 165 cm (5 ft 5 in), Mifflin-St Jeor.
Using your TDEE
- To lose weight, eat below your TDEE. A deficit of about 550 kcal a day loses roughly 0.5 kg (1.1 lb) a week. The weight loss calculator works out the deficit for a goal weight and date, and warns you if the pace is unsafe.
- To maintain, eat around your TDEE and check your weight trend every few weeks.
- To build muscle, eat a little above it, about 250–500 kcal a day, and train with weights.
- To plan what you eat, turn your calorie target into grams of protein, carbs and fat with the macro calculator.
Why the result is an estimate
Equations predict the average for people like you. Two people with the same age, height and weight can differ by a few hundred calories a day, mostly because of muscle mass and everyday movement. Fitness trackers vary even more. The most reliable way to find your real TDEE is to track your food intake and weight for 2–4 weeks: if your weight holds steady, your average intake is your TDEE.
Frequently asked questions
What does TDEE stand for?
Total daily energy expenditure: the total number of calories your body burns in 24 hours. It includes your basal metabolic rate, the energy used to digest food, deliberate exercise and all your everyday movement.
Is TDEE the same as maintenance calories?
Yes, for practical purposes. If you eat roughly your TDEE on average, your weight stays about the same. Eat less and you lose weight; eat more and you gain.
What is the difference between BMR and TDEE?
BMR (basal metabolic rate) is what you would burn lying still all day. TDEE is BMR plus everything else you do. For most people TDEE is 1.2 to 1.9 times their BMR, depending on how active they are.
How accurate is a TDEE calculator?
For most healthy adults the estimate is within about 10% of the real figure, but individuals vary. Treat the result as a starting point. Eat at that level for 2 to 3 weeks, watch your weight trend, and adjust by 100 to 200 kcal if it is moving when you expected it to hold steady.
Which activity level should I choose?
Most people overestimate how active they are. If you have a desk job and work out 3 times a week, lightly active (1.375) is usually closer than moderately active. Pick the lower option if you are unsure, then adjust based on your results.
Should I eat back the calories I burn exercising?
Not if you already chose an activity level that includes your training. The activity factor already counts your exercise, so adding fitness-tracker calories on top would count it twice.
Why is my TDEE lower than I expected?
TDEE falls as you get lighter and as you get older, and the equations assume average body composition. Fitness trackers often overestimate calories burned, so they can make a calculator look low by comparison.