TDEE calculator: total daily energy expenditure

What is TDEE

TDEE, total daily energy expenditure, is everything you burn in a day. It is the number that decides whether your weight goes up, down or stays where it is: eat at your TDEE and you maintain, eat below it and you lose. It has four parts.

• BMR, the energy to keep you alive at rest: usually 60 to 70 percent of the total.
• The thermic effect of food, the cost of digesting what you eat: about 10 percent, a little more on a high-protein diet.
• Exercise: for most people a smaller share than they expect, often 5 to 10 percent.
• NEAT, non-exercise activity such as walking, standing, doing chores and fidgeting. It varies more between people than any other part, by hundreds of calories a day between people of the same size.

TDEE vs BMR

BMR is what you burn lying still; TDEE is the whole day. You eat against your TDEE, never your BMR. The BMR calculator compares the equations for the resting part in detail.

How to calculate TDEE

TDEE = BMR × activity factor. This calculator estimates BMR with the Mifflin-St Jeor equation, then multiplies it by one of five factors:

An example: a 35-year-old woman, 5 ft 5 in and 160 lb, has a BMR of about 1,420 calories. At the light level, her TDEE is about 1,420 × 1.375 ≈ 1,955 calories a day.

The factors are a convention, not a measurement. They come from older estimates of the energy cost of different lifestyles and have never been well validated, which is why the next two sections matter.

Which activity level to choose

Pick the level that describes most weeks, not your best week. Most people overestimate their activity, and the factor already includes ordinary movement, so a desk job with three gym sessions a week is "light". If you are torn between two levels, choose the lower one.

Fitness trackers do not settle the question. A 2017 Stanford study tested seven wrist-worn devices and found that none estimated energy expenditure to within 20 percent. Their step counts are a useful trend; their calorie counts are not.

Checking your TDEE against your own weight

Any equation is a starting estimate. Your real TDEE can be worked out from your own data:

1. Log what you eat for two to three weeks, as honestly as you can.
2. Weigh yourself most mornings and compare the weekly averages, not single days, at the start and the end.
3. Your TDEE is your average daily intake plus (pounds lost × 3,500 ÷ number of days). If you gained, subtract instead.

For example, eating an average of 2,000 calories a day and losing 1.5 pounds over 21 days gives a TDEE of about 2,000 + (1.5 × 3,500 ÷ 21) = 2,250 calories. The first week of any diet change includes water weight, so the estimate gets better the longer you track.

Why TDEE changes over time

TDEE falls as you lose weight, because a smaller body costs less to run and to move. Over a long diet it falls a little further than the weight loss alone predicts, partly because people move less without noticing. That is why a deficit that worked at the start stops working months later, and why the numbers here are worth recalculating after every 10 pounds or so. Age matters less than people think; there is more on that on the BMR calculator.

Using TDEE for weight loss

Subtract a deficit from your TDEE to lose weight. The calorie deficit calculator does that for the rate you choose and shows how long it will take. To turn the calories into grams of protein, carbs and fat, use the macro calculator.