A lean-mass perspective
Use body-fat percentage to estimate resting energy needs, then account for daily movement.
Add a meal or a weigh-in. Your records stay on this device until you choose to sync.
Compare formulas, set a pace and turn energy needs into a practical macro target.
Log meals and weigh-ins. Follow a smoother trend, with no pressure to make every day perfect.
Pro uses complete intake records and trend weight to make measured weekly adjustments.
Lean body mass is body weight multiplied by one minus the body-fat fraction. The equation estimates BMR as 370 + 21.6 × lean mass in kilograms. TDEE then applies an activity multiplier. Unlike Mifflin-St Jeor, the equation does not use age or sex directly; the quality of the body-fat estimate therefore matters.
Home scales, tape measurements and clinical body-composition methods can disagree. An imprecise body-fat percentage carries through to the calorie estimate. If you do not have a reliable measurement, compare the result with Mifflin-St Jeor. The optional Navy circumference tool is also an estimate and should not be treated as a clinical measurement.
One shared calculation engine, with a focus that fits your goal.
Yes. Katch-McArdle needs lean mass derived from body weight and body-fat percentage. Without it, choose Mifflin-St Jeor instead of assuming an arbitrary body composition.
No. It can be useful when body composition is known, but measurement errors can outweigh the benefit. Actual intake and weight trends add useful context.
