TDEE / Daily Maintenance Calories Calculator
Start with Mifflin-St Jeor (and Katch-McArdle if body fat is measured), then dial in your real maintenance from 14-28 days of calories and morning weight.
Starting estimate — the equation
Mifflin-St Jeor is the baseline. Enter a measured body-fat percentage to also get the Katch-McArdle lean-mass estimate. Use whichever number to begin; it is only a starting point.
Your inputs
Gender
Activity & goal
â–¸Optional: add a measured body-fat %
Only fill this in if you have a real measurement (DEXA, hydrostatic, or skilled calipers) — a guessed number does more harm than leaving this blank.
Result
Maintenance calories
2633 kcal/day
Mifflin-St Jeor BMR multiplied by your activity factor.
BMR (Mifflin-St Jeor)
1699 kcal/day
Resting energy before activity is included.
Maintenance (Katch-McArdle)
2633 kcal/day
Lean-mass method at 18% body fat. Trust it only if that number is measured, not guessed.
Your TDEE is the calorie estimate most useful for maintenance, fat loss, or gaining phases. Treat the equation as a starting point and correct it with a few weeks of your own intake and weight data.
This is only a starting estimate. Log daily calories and morning weight for 14-28 days, then use the adaptive estimate below.
Adaptive estimate — your own data
Log daily calories and a consistent morning weight for 14-28 days. The tool fits a line to your weight trend and works backwards to the maintenance calories you were actually running. This beats any equation for your individual number.
Daily log
0 of 14 rows complete. Weigh first thing, after the toilet, before eating or drinking. Entries save to this browser only.
Result
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Fill in at least 7 complete days of calories and morning weight and your maintenance estimate appears here. Aim for 14-28 days for a number you can trust. Try Sample data to see it work.
Estimates only. The 7,700 kcal per kilogram figure is an average, day weights carry water noise, and maintenance shifts as body weight and activity change. Recalculate every 2-4 weeks and adjust from the trend, not from a single day.
â–¸How the adaptive estimate is calculated
A weight change of 1 kg over these timescales is treated as about 7,700 kcal of stored (or missing) energy — mostly fat, plus some lean tissue, glycogen and water. Fitting a straight line to 14-28 morning weights averages out the daily water swings and gives a trend in kg/week. Multiply that trend by 7,700 ÷ 7 to get the daily surplus or deficit you were running, then:
adaptive maintenance
  = average intake − (weekly weight change × 7,700 ÷ 7)
Why it beats an equation: Mifflin-St Jeor and Katch-McArdle predict an average person of your size. This uses your intake, your non-exercise movement, your digestion and your training, because all of it already shows up in the scale trend. The cost is time — you need a couple of honest weeks first.
- Weigh at the same time daily: after the toilet, before food or drink.
- Log calories as accurately as you can; consistent small errors matter less than random big ones.
- 7-13 days is a direction, 14-20 is usable, 21+ is solid. Re-run every 2-4 weeks.
- Women: compare the same phase of consecutive cycles, since water weight shifts across the month.