What is TDEE and why does it matter?
Total Daily Energy Expenditure (TDEE) is the total number of calories your body burns in a 24-hour period, including everything from breathing and organ function to exercise and fidgeting. It is your caloric maintenance level — the amount of food you need to eat to neither gain nor lose weight.
TDEE is calculated by multiplying your Basal Metabolic Rate (BMR) — the calories burned at complete rest — by an activity multiplier. The Mifflin-St Jeor equation is the most accurate BMR formula for most people and is what modern TDEE calculators use.
Mifflin-St Jeor BMR:
Men: (10 × weight kg) + (6.25 × height cm) − (5 × age) + 5
Women: (10 × weight kg) + (6.25 × height cm) − (5 × age) − 161
TDEE = BMR × Activity Multiplier
Step 1: Enter your stats correctly
The four inputs you need are: age, sex, weight, and height. Use your current weight in kg (or lbs) and height in cm (or feet/inches). Age matters because BMR declines roughly 1–2% per decade after age 20 as muscle mass naturally decreases.
Weigh yourself in the morning after using the bathroom and before eating for the most consistent reading. If your weight fluctuates significantly, use a rolling 7-day average.
Step 2: Choose the right activity level
The activity multiplier is where most people make mistakes — and almost always in the direction of overestimating. Here are the standard multipliers and what they actually mean:
| Level | Multiplier | Description |
|---|---|---|
| Sedentary | 1.2 | Desk job, little or no exercise |
| Lightly active | 1.375 | Light exercise 1–3 days/week |
| Moderately active | 1.55 | Moderate exercise 3–5 days/week |
| Very active | 1.725 | Hard exercise 6–7 days/week |
| Extra active | 1.9 | Physical job + hard training daily |
If you sit at a desk all day but go to the gym 3 times per week, choose lightly active (1.375) — not moderately active. Most office workers with a gym habit overestimate this and wonder why they are not losing weight at their calculated calorie target.
Step 3: Interpret your TDEE result
Your TDEE is a starting estimate, not a perfect number. Individual variation in metabolism, gut microbiome, NEAT, and hormonal status means actual maintenance calories can vary by ±10–15% from the calculated figure.
Treat your TDEE as a hypothesis. Eat at your calculated maintenance for 2 weeks while tracking food accurately. If your weight stays stable, the estimate is accurate. If you gain, your real TDEE is lower; if you lose, it is higher. Adjust accordingly.
Step 4: Set your calorie target based on your goal
Once you have your TDEE, apply the appropriate adjustment:
- Weight loss: TDEE minus 300–500 kcal/day (moderate deficit)
- Aggressive weight loss: TDEE minus 500–750 kcal/day (with high protein to protect muscle)
- Maintenance: Eat at TDEE
- Muscle gain (lean bulk): TDEE plus 200–300 kcal/day
- Muscle gain (standard bulk): TDEE plus 300–500 kcal/day
Common mistakes when using TDEE
Forgetting to recalculate: As you lose weight, your BMR drops. Recalculate your TDEE every 5–10 kg of weight change, or every 6–8 weeks, to keep your targets accurate.
Not tracking food accurately: Research consistently shows people underestimate their food intake by 20–50%. Even experienced trackers miss things like cooking oils, sauces, and drinks. Weigh food with a kitchen scale when starting out.
Eating back exercise calories: If you chose an activity level that already includes your exercise, do not add those calories back on top. Only eat back exercise calories if you selected sedentary and added all exercise separately.