Estimate your activity level for TDEE.
TDEE calculators ask you to pick an activity multiplier from vague descriptions, which is where most estimates go wrong. This derives the multiplier instead: structured exercise is scored against the 150-minutes-a-week guideline, and daily steps capture the non-exercise movement that often matters more. Multiplying basal metabolic rate by the resulting factor gives daily energy expenditure and the calories you burn above rest.
Derived activity multiplier
Activity factor = 1.2 + 0.18 x (weekly exercise minutes / 150) + 0.22 x step score, capped at 2.05; TDEE = BMR x activity factor
Energy expenditure estimates are approximate and vary with body composition, medication, hormones and health conditions. Consult a healthcare professional before making significant dietary changes.
Because the labels are interpreted very differently by different people, and a one-step error in the multiplier moves TDEE by 200-300 calories a day. Deriving it from exercise minutes and steps removes most of that guesswork.
Non-exercise activity is the largest source of variation between two people with identical workouts. Someone walking 12,000 steps a day burns substantially more than a desk-bound person doing the same gym sessions.
It is an estimate. Track weight over two to three weeks at a steady intake and adjust the multiplier until the trend matches your goal.