How to use it
- Step 1Pick your sex and enter your age, height and weight (switch to Metric if you prefer kg and cm).
- Step 2Choose the activity level that matches a typical week, not your best week.
- Step 3Add your body fat percentage if you know it; the tool then switches to the Katch-McArdle formula.
- Step 4Read your TDEE, then use the goal table for a daily target to lose, keep or gain.
Explainer · 0:21
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- Your body burns energy even at rest. That's your BMR: about 1,528 kcal a day for a 35-year-old woman who is 5 ft 6 in and 180 lb.
- Daily movement multiplies it. Light activity is × 1.375, so 1,528 becomes about 2,101 kcal. That's your TDEE.
- Eat about 500 kcal less than your TDEE and you're in a deficit: around 1,601 kcal a day.
- That's roughly 1 lb a week at first. Loss slows as your body adapts, so treat the number as a starting point and adjust.
Step 1: your resting burn
Without a body fat number, the tool uses the Mifflin-St Jeor equation, the formula most dietitians use for adults:
- Men: 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5
- Women: 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161
With body fat, it uses Katch-McArdle: 370 + 21.6 × lean mass (kg). That's often closer for very muscular people.
Step 2: multiply by activity
| Activity level | Multiplier |
|---|---|
| Sedentary: desk job, little exercise | 1.2 |
| Light: exercise 1 to 3 days a week | 1.375 |
| Moderate: exercise 3 to 5 days a week | 1.55 |
| Very active: hard exercise 6 to 7 days | 1.725 |
| Extra active: physical job plus training | 1.9 |
Worked example: a 35-year-old woman, 5 ft 6 in (167.6 cm), 180 lb (81.6 kg): BMR = 816 + 1,048 − 175 − 161 = 1,528 kcal. Lightly active: 1,528 × 1.375 = 2,101 kcal a day.
How accurate it is
Mifflin-St Jeor lands within about 10% of measured resting burn for most adults, but individuals can be further off. Treat your TDEE as a starting estimate: eat at the target for 2 to 3 weeks, watch your weekly average weight, and adjust by 100 to 200 kcal.
Calorie targets below 1,200 kcal (women) or 1,500 kcal (men) are raised to those levels, a common floor without medical supervision. More on why calculators disagree in How TDEE is calculated.
Prefer a chart? See TDEE by weight: precomputed tables for common inputs.
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OpenCommon questions
Is TDEE the same as maintenance calories?
Yes. TDEE is the number of calories you burn in a typical day, so eating that amount should keep your weight roughly stable.
Should I eat below my BMR to lose weight?
Usually not. Your BMR covers basic body functions, and most people lose weight well by eating between their BMR and their TDEE.
Why is my TDEE different on other sites?
Most sites use the same formula but different activity multipliers or rounding. The activity level you pick changes the result far more than the formula does.
How often should I recalculate?
Every 10 to 15 lb lost, or when your activity changes. A smaller body burns less, so your target drifts down as you lose weight.
Does TDEE change on a GLP-1 medicine?
Your energy needs don't drop just because your appetite does. Use the TDEE on a GLP-1 tool to see how your reduced intake compares with what you burn.