TDEE:
BMR x activity multiplier

How many calories do you burn in a day?

Your total daily energy expenditure (TDEE) is your resting calorie burn multiplied by an activity factor. With a BMR of 1,600 kcal and a moderate factor of 1.55, TDEE is about 2,480 kcal a day. It is an estimate, not medical advice.

The calculator needs your BMR as an input, in kcal per day, so work that out first. Then you pick one of five activity multipliers.

Think of BMR as the engine idling and the multiplier as the extra fuel for moving around. Two people with the same BMR can have TDEEs that differ by hundreds of kcal because their days look so different.

The five multipliers are fixed options in the calculator, so you choose the closest match rather than typing your own number.

The TDEE formula and a worked example

What the five multipliers give

The multipliers are commonly described as sedentary (1.2), lightly active (1.375), moderately active (1.55), very active (1.725) and extra active (1.9). For a BMR of 1,600 kcal:

The gap between the lowest and highest is 1,120 kcal for the same person, which shows how much the choice of multiplier matters.

The same person at 1.2 burns 1,920 kcal and at 1.725 burns 2,760, a difference of 840 kcal a day. That is why picking one level too high gives a number that does not match real life.

Choosing an honest activity level

Most people overestimate. A desk job with three workouts a week often fits the lower-middle multipliers, not the top ones. Choose the one that matches an ordinary week, including days off, not your best week.

• Count total movement, not just gym time: walking, stairs, housework and standing at work.
• If you are between two levels, take the lower one.
• Reassess when your routine changes, for example a new job or training block.

Checking the number against real life

Treat TDEE as a starting point. Eat at that level for two or three weeks and watch your weight. If it stays steady, the estimate is close; if it drifts, adjust by a small amount and try again.

Keep notes: your average weight each week, roughly what you ate, and how active you were. After a few weeks you will see whether the estimate needs a nudge up or down.

Common mistakes with TDEE

• Entering weight in kilograms instead of BMR in kcal.
• Choosing 1.725 or 1.9 because of one hard workout.
• Treating the result as a target for eating, not a starting estimate.
• Counting exercise calories twice, once in the multiplier and again from a fitness tracker.

Remember too that TDEE shifts as your body changes. If your weight or routine changes by a lot, recalculate your BMR first and then reapply the multiplier.