TDEE Calculator
TDEE is your maintenance level: eat this and your weight holds. It is your resting metabolic rate multiplied by an activity factor.
Your results
An estimate with a real margin — activity multipliers are broad, and two people of the same size can differ by several hundred calories. Treat it as a starting point and correct it against two weeks of weight data.
How TDEE is calculated
Two steps. First your basal metabolic rate — what you would burn lying still all day — from the Mifflin-St Jeor equation:
- Men: (10 × kg) + (6.25 × cm) − (5 × age) + 5
- Women: (10 × kg) + (6.25 × cm) − (5 × age) − 161
Then multiplied by an activity factor from 1.2 (sedentary) to 1.9 (extremely active). That multiplier is where nearly all the error lives — it bundles your job, your walking, your training and your fidgeting into one number.
Why the number is only a starting point
A good equation gets most people within about 10%. On a 2,600 kcal maintenance that is 260 kcal — larger than many people's intended deficit. Two people of identical height, weight, age and stated activity can genuinely differ by 400 kcal, mostly through spontaneous daily movement.
So use this figure to start, then measure. Eat at it for two weeks, weigh yourself daily, and compare week one's average with week two's. If your weight held, that is your real maintenance — a number no calculator can give you.
Common questions
Which activity level should I choose?
Be honest and err low. Most people who train three times a week and have a desk job are 'lightly active', not 'moderately active'. The second table in the results shows what each level would give you, so you can see how much the choice is worth — usually 300 kcal a step.
What are the calorie targets in the table based on?
A percentage of your body weight per week, which scales with your size rather than applying the same 500 kcal to everyone. Losing 0.5–1.0% per week keeps most of the loss as fat; gaining more than about 0.5% per week mostly adds fat, because muscle growth is limited by training rather than by calories.
Why is my fitness tracker's number different?
Wearable expenditure estimates are frequently out by 20% or more, usually high. Your weight trend is more reliable than either.
Should I eat my TDEE on rest days too?
Simplest to keep intake consistent. Weekly total is what drives the outcome, and recovery happens on rest days.
How do I use this to lose weight?
Subtract 300–500 kcal and target 0.5–1.0% of body weight lost per week. The calorie deficit calculator does the arithmetic.
Related calculators
Track the numbers, not just calculate them
MyFitsy stores your weight, measurements and every session, so the figures above become a trend instead of a one-off.
