What is TDEE? How to work out the calories you burn a day
TDEE stands for total daily energy expenditure: roughly how many calories your body uses in a normal day, including everything from breathing to walking to the gym. It is the starting point for almost every calorie target, because eating around your TDEE keeps your weight steady, a bit less usually leads to weight loss, and a bit more to weight gain.
What TDEE is made of
- Resting energy (BMR): the energy your body needs just to stay alive at rest. For most people this is the biggest part, often well over half of the total.
- Movement: everything from fidgeting and housework to walking and exercise.
- Digesting food: your body uses a little energy to process what you eat.
Step 1: estimate your BMR
A widely used formula is Mifflin–St Jeor:
- Men: (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5
- Women: (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161
Example: a 35-year-old man, 180 cm and 80 kg: 800 + 1,125 − 175 + 5 = 1,755 kcal.
If you know your body fat percentage, the Katch–McArdle formula uses lean mass instead and can suit people whose build is far from average: 370 + (21.6 × lean mass in kg).
Step 2: multiply by your activity level
- Mostly seated: × 1.2
- Lightly active (light exercise 1–3 days a week): × 1.375
- Moderately active (3–5 days a week): × 1.55
- Very active (hard exercise most days, or a physical job): × 1.725
Our example man is moderately active: 1,755 × 1.55 = about 2,720 kcal a day.
Step 3: treat it as an estimate
Every formula is an average of many people, so your real number could be a few hundred calories different. The best way to find out is to eat around your estimate for two to three weeks while logging honestly, and watch your weight trend. If it holds steady, that is your real maintenance level. If it creeps up or down, adjust by about 100–200 calories and watch again.
What to do with your TDEE
- To maintain weight, eat around it.
- To lose weight gently, eat a modest percentage below it. We explain how big in our guide to a safe calorie deficit.
- To gain weight, eat a little above it.
Common questions about TDEE
Does my TDEE change when I lose weight? Yes. A lighter body uses a little less energy, so your TDEE falls as your weight does. It is worth recalculating after every few kilograms, or every month or two.
Do I eat back the calories from exercise? Not if you picked an activity level that already includes your usual exercise. The multipliers above are designed to cover a typical week, so adding exercise calories on top counts it twice. Watches and gym machines also tend to overestimate what you burn.
Is TDEE the same as BMR? No. BMR is only the energy for staying alive at rest. TDEE is BMR plus everything you do.
Why does my watch show a different number? Devices use their own estimates, and they can be out by 20% or more. Treat any single source as a guess and go by your real-world results.
The most common mistake
Most people pick an activity level that is too high. A desk job with three gym sessions a week is usually "lightly active" or "moderately active", not "very active". If you are unsure, choose the lower option and adjust upwards if your weight keeps falling when you want it to stay steady.
Foodie works out your TDEE for you from your age, sex, height, weight and activity, shows the working, and lets you change any number you like. Try Foodie free.