How to calculate your TDEE (and actually use it)
Your TDEE is the number every diet math starts from. Here is how to work it out and turn it into a calorie target you can hit.
Total Daily Energy Expenditure, or TDEE, is how many calories you burn in a full day. Every calorie target you have ever seen starts here. Get this number roughly right and the rest of your nutrition plan has a foundation. Get it wrong and you spend months guessing.
What goes into TDEE
TDEE has two parts. The first is your Basal Metabolic Rate (BMR), the energy your body uses at complete rest to keep you alive. The second is everything you do on top of that: walking, training, fidgeting and digesting food. You estimate BMR from a formula, then multiply it by an activity factor to reach TDEE.
The Mifflin-St Jeor formula
For men, BMR = 10 x weight(kg) + 6.25 x height(cm) - 5 x age + 5. For women, the final term is -161 instead of +5. Then pick your activity factor and multiply.
- Sedentary, desk job, little exercise: 1.2
- Light, exercise one to three days a week: 1.375
- Moderate, exercise three to five days a week: 1.55
- Active, exercise six to seven days a week: 1.725
- Athlete, hard training plus a physical job: 1.9
A worked example
Take a 30-year-old man, 80 kg, 180 cm, training four days a week. BMR is 10 x 80 + 6.25 x 180 - 5 x 30 + 5, which is 1780 kcal. Multiply by 1.55 for moderate activity and TDEE lands near 2760 kcal per day.
Turn TDEE into a target
To lose fat, eat about 500 kcal below TDEE. To maintain, eat at TDEE. To add lean mass without excess fat, add around 300 kcal. These are starting points, not rules carved in stone.