Body composition estimator
See what your body-fat target could mean in numbers.
Estimate body composition, target weight, the approximate amount of fat to lose, and how activity changes estimated daily energy expenditure.
Your starting point and target
50–250 kg
Selected: 30%
Body-fat percentage is approximate; appearance varies between individuals.
Selected: 15%
Choose a lower body-fat target.
Moderately active ×1.55
Broad predictive activity categories, not measurements.
Estimated target weight—
Estimated fat to lose—
Target body fat—
Current → target
Current
—
Estimated body fat—
Estimated fat mass—
Estimated lean mass—
→
Selected target
—
Target body fat—
Estimated target fat mass—
Lean mass—
Your estimated target weight is based on reaching the selected body-fat level while maintaining your estimated lean mass — not simply subtracting an arbitrary number of kilograms from the scale.
The numbers
Approx. energy in 1 kg fat~7,700 kcal
Approx. fat-energy equivalent—
Educational approximation, not exact physiology.
Mathematical time estimates
~500 kcal/day
——
~750 kcal/day
——
~1,000 kcal/day
——
Mathematical comparisons only; a larger gap is not automatically more appropriate.
Daily energy expenditure and supply
Estimated BMR—
+
Activity—
=
Theoretical TDEE—
500 kcal/day gap
—
Theoretical TDEE
—
Illustrative supply
Difference: ~500 kcal/day energy gap
Activity changes estimated TDEE and illustrative supply. It does not change the body-composition target.
Calculation basis
Target weight assumes estimated lean mass is maintained. Fat-energy equivalent uses ~7,700 kcal/kg. BMR uses Katch-McArdle. TDEE uses the selected activity factor. Time estimates use 500 / 750 / 1,000 kcal/day.
