TDEE calculator

Estimate the calories you burn in a day including activity — then see targets for losing, maintaining or gaining weight.

How this calculator works

TDEE is your total calorie burn for a day: BMR plus everything else — moving around, exercise, digesting food and the small cost of staying upright. The usual approach is to multiply BMR by an activity factor that ranges from 1.2 for a completely sedentary desk job to 1.9 for athletes training twice a day. It is a rough multiplier, which is why the estimate can be off for people whose real activity does not match a label.

The weight-change targets are based on the widely used approximation that 500 calories a day below maintenance produces roughly 1 lb of loss a week, since a pound of fat stores about 3,500 calories. That rule works for about 8–12 weeks before metabolic adaptation, water shifts and changes in movement slow it down. For sustainable loss, a 300–500 calorie deficit and resistance training to preserve muscle is usually the better plan than an aggressive cut.

The formula

TDEE = BMR × activity factor, where BMR comes from Mifflin-St Jeor:

Activity factors: 1.2 sedentary, 1.375 light, 1.55 moderate, 1.725 very active, 1.9 extremely active.

Worked example

With a BMR of 1,783 and the selected activity level, maintenance calories are 2,763 a day. A 500-calorie deficit gives 2,263 for roughly 1 lb of loss a week, while a lean gaining phase targets 3,063.

Common mistakes

• Overestimating activity. Most office workers who exercise three times a week land in the light-to-moderate range, not very active. Start conservative.
• Cutting too hard. Very large deficits reduce adherence, encourage muscle loss and slow metabolic rate. 15–25% below TDEE is a more sustainable target.
• Eating back all exercise calories. Calorie burn from cardio is often overestimated by machines and watches, which double-counts activity already included in the TDEE factor.