How this TDEE calculator works
The calculator works in two steps:
- Estimate your BMR (basal metabolic rate), the energy your body uses at complete rest, from your sex, age, height and weight. If you know your body-fat percentage, the estimate can use your lean mass instead.
- Multiply by an activity factor, from 1.2 for a mostly seated day up to 1.9 for hard daily training. The result is your TDEE.
For example, a 30-year-old woman who is 5′5″ and 150 lb has a Mifflin-St Jeor BMR of about 1,401 calories. At “lightly active” (×1.375) her TDEE is about 1,927 calories a day. That example is the default view above.
Activity levels explained
| Level | Typical week | Factor |
|---|---|---|
| Sedentary | Little or no exercise, mostly sitting (desk job) | ×1.2 |
| Lightly active | Light exercise or sports 1–3 days a week | ×1.375 |
| Moderately active | Moderate exercise or sports 3–5 days a week | ×1.55 |
| Very active | Hard exercise or sports 6–7 days a week | ×1.725 |
| Extra active | Very hard daily training, or exercise plus a physical job | ×1.9 |
These multipliers are a convention, not a measurement. People overestimate their activity more often than they underestimate it, so if two levels both seem to fit, start with the lower one and check it against your weight trend.
Which formula should you pick?
- Mifflin-St Jeor is the default. In a 2005 systematic review for the American Dietetic Association it estimated resting metabolic rate within 10% of measured values more often than the other equations tested.
- Katch-McArdle uses lean body mass, so it can suit people who know their body-fat percentage, especially very muscular people for whom weight-based equations may run low. It is only as good as the body-fat number you enter.
- Revised Harris-Benedict is the 1984 update of the classic 1918 equation. It usually comes out a little higher than Mifflin-St Jeor.
The “BMR by formula” box shows all three side by side, so you can see how much they differ for you.
What to do with your TDEE
Treat the number as a first guess. If you want to keep your weight steady, eat around it for two to four weeks and watch your average weight. If the average stays flat, that intake is close to your real maintenance. If it drifts, adjust by 100 to 200 calories and keep watching. The guide how to find your maintenance calories walks through it.
If you want gradual change, the table above shows gentle ranges of about 0.5 to 1 lb a week. Slower changes are generally easier to keep up. Estimates vary from person to person and this is not medical advice; if eating or weight feels stressful, a doctor or registered dietitian can help.
Frequently asked questions
What does TDEE stand for?
TDEE means total daily energy expenditure: the calories your body uses in a full day, including what it burns at rest, digesting food, everyday movement and exercise. It is the same idea as “maintenance calories”.
Which formula does this calculator use?
By default it uses the Mifflin-St Jeor equation (1990). If you enter a body-fat percentage, Auto switches to Katch-McArdle, which works from lean body mass. You can also pick the revised Harris-Benedict equation (1984). All three are explained on the methodology page.
How accurate is a TDEE calculator?
It is a starting estimate. Equations like Mifflin-St Jeor predict resting energy use within about 10% for many people, but individuals can sit well above or below the estimate, and the activity multiplier adds more uncertainty. Your own weight trend over a few weeks is the best check. See are TDEE calculators accurate?
Which activity level should I choose?
Pick the level that matches a typical week, not your best week. Most people with desk jobs who exercise a few times a week fit “lightly active” or “moderately active”. If you are unsure, choose the lower one. The activity level calculator can help.
Is this calculator suitable for everyone?
It is designed for adults. It is not meant for children or teens, during pregnancy or breastfeeding, or for people managing a medical condition that affects weight or metabolism. In those cases a doctor or registered dietitian can give a better estimate.