What is TDEE?
Your total daily energy expenditure (TDEE) is the number of calories you burn in a day. Eat that many and your weight should stay about the same, which is why it's also called your maintenance calories. Eat less and you're in a calorie deficit; eat more and you're in a surplus.
How it's calculated
The calculator first estimates your basal metabolic rate (BMR), the energy your body uses at rest, with the Mifflin-St Jeor equation:
BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5 (male) or − 161 (female)
It then multiplies your BMR by an activity factor, from 1.2 if you mostly sit to 1.9 if you have a physical job and train hard, to account for everything else you do in a day.
Use it as a starting point
Any formula is an estimate, and real people vary by a few hundred calories either way. If you wear a fitness tracker, the calories burned it records are usually a better daily guide. Either way, the best check is your weight over a few weeks: if it isn't moving as expected, adjust by 100 to 200 calories and keep going.
Questions
How many calories do I burn a day?
Most adults burn somewhere between 1,600 and 3,000 calories a day, depending mainly on body size, sex, age and how active they are. Enter your details above for a personal estimate.
What is the difference between BMR and TDEE?
BMR is the energy you would use lying still all day. TDEE adds everything else, including walking, work, exercise and digesting food, so it is always higher than BMR.
How many calories should I eat to lose weight?
A common approach is to eat about 500 calories a day below your TDEE, which works out at roughly 1lb (0.45kg) a week. The calorie deficit calculator can work out a target for a goal weight and date.
Which activity level should I choose?
Choose based on a typical week, not your best one. Most people overestimate their activity, so if you are between two levels, pick the lower one.
Why do I ask for sex?
The Mifflin-St Jeor equation has different constants for men and women, because of average differences in body composition. It is only used for this calculation.