To calculate TDEE, first find your basal metabolic rate (BMR) with the Mifflin-St Jeor equation, then multiply it by an activity factor between 1.2 and 1.9. The result is your maintenance calories — the number of calories you burn in a typical day. Eat that amount and your weight stays roughly stable; eat less and you lose weight; eat more and you gain.
TDEE stands for total daily energy expenditure. It is the single most useful number in weight management, because every calorie target — losing, maintaining, or gaining — is built on it. This guide shows the two-step calculation, the activity multipliers, three worked examples, and how to check your result against two weeks of real data.
What Is TDEE?
TDEE is the total number of calories your body burns in a day. It has four parts. The largest is your basal metabolic rate (BMR): the energy used at rest to breathe, circulate blood, and keep your organs running, usually 60 to 70 percent of the total. Next is the thermic effect of food, about 10 percent. Then comes exercise activity, and finally NEAT — non-exercise activity thermogenesis — the energy of everything else you do while awake: walking, standing, fidgeting, and chores.
The two-step formula rolls all four parts into one number: BMR estimates the resting part, and the activity multiplier scales it up to cover movement, exercise, and digestion. A free calorie calculator runs the same two steps, but doing it by hand once means you can spot a wrong answer instantly.
Step 1: Calculate BMR With Mifflin-St Jeor
The Mifflin-St Jeor equation, published in 1990, is the formula most dietitians reach for, because in validation studies it predicted resting energy within 10 percent of the measured value for more people than the older Harris-Benedict equation. It uses weight, height, age, and sex:
- Men: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5
- Women: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161
Use kilograms and centimetres. To convert pounds to kilograms, divide by 2.2046; to convert inches to centimetres, multiply by 2.54. Entering pounds into a formula built for kilograms inflates the result by more than double. Each term has a meaning: weight contributes 10 calories per kilogram, height adds 6.25 per centimetre, age subtracts 5 per year, and the final constant (+5 men, −161 women) reflects average differences in muscle mass.
Step 2: Multiply BMR by Your Activity Factor
Your BMR is what you would burn lying in bed all day. The activity multiplier scales it to your real life:
| Activity level | What it looks like | Multiplier |
|---|---|---|
| Sedentary | Desk job, little or no exercise | 1.2 |
| Lightly active | Light exercise 1–3 days a week | 1.375 |
| Moderately active | Moderate exercise 3–5 days a week | 1.55 |
| Very active | Hard exercise 6–7 days a week | 1.725 |
| Extremely active | Physical job plus daily training | 1.9 |
This is where most TDEE calculations go wrong. The multiplier is a judgment call, and most people pick one level too high. A desk worker who goes to the gym three times a week is moderately active, not very active. Picking one level too high adds 150 to 300 calories to the result — enough to erase a weight-loss deficit entirely. When in doubt, pick the lower level.
The formula is simply TDEE = BMR × activity multiplier. The result is your maintenance calories in calories per day.
Worked Example 1: A 30-Year-Old Man, 80 kg, 180 cm, Moderately Active
Step 1 — BMR: (10 × 80) + (6.25 × 180) − (5 × 30) + 5 = 800 + 1,125 − 150 + 5 = 1,780 calories a day.
Step 2 — TDEE: 1,780 × 1.55 (moderately active) = 2,759 calories a day. Eat about 2,759 calories and his weight stays roughly stable.
To lose about 1 pound a week, subtract 500: 2,759 − 500 = 2,259 calories a day. To gain weight, add 300 to 500 instead. The same TDEE anchors every goal — only the adjustment changes.
Worked Example 2: A 30-Year-Old Woman, 65 kg, 170 cm, Moderately Active
Step 1 — BMR: (10 × 65) + (6.25 × 170) − (5 × 30) − 161 = 650 + 1,062.5 − 150 − 161 = 1,401.5 calories a day, rounded to 1,402.
Step 2 — TDEE: 1,401.5 × 1.55 = 2,172.3 calories a day, rounded to 2,172. Her weight-loss target at a 500-calorie deficit is 2,172 − 500 = 1,672 calories a day.
Compare the two examples: same age, same activity level, yet his TDEE is 587 calories higher than hers (2,759 − 2,172 = 587). About 379 of that gap comes from BMR — he is 15 kg heavier, 10 cm taller, and male — and the activity multiplier magnifies the difference.
Worked Example 3: The Same Man, Sedentary vs Very Active
Activity alone can swing TDEE by nearly 1,000 calories. Take the man from Example 1, BMR 1,780, and change only the multiplier:
| Activity level | Multiplier | TDEE |
|---|---|---|
| Sedentary | 1.2 | 1,780 × 1.2 = 2,136 |
| Lightly active | 1.375 | 1,780 × 1.375 = 2,448 |
| Moderately active | 1.55 | 1,780 × 1.55 = 2,759 |
| Very active | 1.725 | 1,780 × 1.725 = 3,071 |
Moving from sedentary to very active adds 3,071 − 2,136 = 935 calories a day to his maintenance — more than a full meal. That is why a TDEE calculated with the wrong activity level looks precise while being wrong by hundreds of calories.
How Accurate Is a Calculated TDEE?
Treat the result as a starting estimate, not a measurement. The Mifflin-St Jeor equation was built from 498 healthy adults aged 19 to 78, and validation studies found it within 10 percent of measured resting energy for about 82 percent of people. That means for roughly one person in five, the estimate is off by more than 10 percent — 200 calories or more on a typical TDEE. The activity multiplier adds further error, since it compresses a whole week of varied movement into one number.
The fix is to test the estimate against your own data. Eat your calculated TDEE for two weeks, track your food, and weigh yourself each morning. Compare weekly averages, not single days, because daily weight fluctuates by 1 to 2 kilograms with water and food. If your weekly average is flat, your TDEE is right. If you lost weight, your real TDEE is higher than the estimate; if you gained, it is lower. Adjust by 100 to 200 calories and test again.
Common Mistakes When Calculating TDEE
| Mistake | What goes wrong | How to fix it |
|---|---|---|
| Using pounds and inches in the formula | The result is inflated by more than double | Convert to kg and cm first |
| Picking too high an activity level | TDEE is 150–300 calories too high, erasing the deficit | Pick the lower level when unsure |
| Using the men’s formula for a woman (or the reverse) | A 166-calorie error before the multiplier, about 230 after it | Check the final constant: +5 men, −161 women |
| Treating the result as exact | Small errors compound into a stalled diet | Test against 2 weeks of real weight data |
| Never recalculating | TDEE falls as you lose weight, so the old target stops working | Recalculate every 5 kg lost, or every 2–3 months |
The third mistake is easy to miss: the 166-calorie sex difference becomes about 166 × 1.375 = 228 calories after a lightly active multiplier, nearly half of a 500-calorie deficit.
How to Use Your TDEE
Once you have the number, the rest is simple arithmetic. For weight loss, subtract 300 to 500 calories a day — the range most dietitians recommend for steady loss of about 0.5 to 1 pound a week. For maintenance, eat at TDEE. For muscle gain, add 300 to 500 calories, with enough protein to support training. To turn your TDEE into a daily target, use a calorie calculator or follow our guide to how many calories you should eat to lose weight, which works through the weight-loss version with two full examples. Our guide to what a calorie deficit is explains how big the deficit should be and what to do when progress stalls.
Your TDEE also moves with your body. Losing 10 kg cuts roughly 100 calories from BMR and about 140 from TDEE at the same activity level, so recalculate whenever your weight changes by 5 kg. If you want the other side of the health picture, your body mass index uses the same weight and height: check it with our free BMI calculator.
FAQ: How to Calculate TDEE
What is the formula to calculate TDEE?
TDEE = BMR × activity multiplier. Calculate BMR with Mifflin-St Jeor — men: (10 × kg) + (6.25 × cm) − (5 × age) + 5; women: the same minus 161 instead of plus 5 — then multiply by 1.2 (sedentary) to 1.9 (extremely active). A calorie calculator runs the same formula if you want to skip the arithmetic.
How do I calculate my TDEE by hand?
Work out your BMR with Mifflin-St Jeor, pick your activity factor honestly (1.2 sedentary, 1.375 lightly active, 1.55 moderately active, 1.725 very active, 1.9 extremely active), and multiply. Example: a 30-year-old man, 80 kg, 180 cm, moderately active — BMR 1,780 × 1.55 = 2,759 calories a day.
What activity level should I choose for TDEE?
Count your real week, not your best week. Desk job with no exercise is sedentary (1.2); light exercise 1–3 days a week is lightly active (1.375); moderate exercise 3–5 days a week is moderately active (1.55). When in doubt, choose the lower level.
Is TDEE the same as maintenance calories?
Yes. TDEE and maintenance calories are the same number: the calories you burn in a typical day. Eating at TDEE keeps your weight roughly stable; eating below it creates the deficit that drives weight loss.
How often should I recalculate my TDEE?
Recalculate whenever your weight changes by about 5 kg, or every 2 to 3 months. Your TDEE falls as you lose weight — a 10 kg loss cuts roughly 140 calories a day from TDEE at the same activity level.
Why does my TDEE calculator disagree with my fitness tracker?
Trackers estimate burn from movement sensors and heart rate, and they commonly overestimate exercise calories by 25 to 40 percent. A formula-based TDEE is usually the steadier starting point.