Race Weight Target Calculator
Estimate a performance "race weight" from your current weight, body-fat percentage and a realistic target body fat — protecting lean mass, not just cutting pounds.
How it works
Lean mass = weight × (1 − body-fat%) · Target weight = lean mass ÷ (1 − target body-fat%)
Race weight is not just "lighter" — it is losing fat while keeping the muscle that produces power. This calculator freezes your current lean mass and computes the weight you would reach at a lower body-fat percentage, so the whole loss comes from fat. Chasing a scale number instead risks shedding muscle and sabotaging performance.
Worked example
At 70 kg and 18% body fat, lean mass is 70 × 0.82 = 57.4 kg. To reach 12% body fat: 57.4 ÷ (1 − 0.12) = 65.2 kg — about 4.8 kg of fat to lose, roughly 10 weeks at half a kilo a week.
Frequently asked questions
What body-fat percentage should I target?
It is individual and sport-specific. Many endurance athletes perform well around 8–12% (men) or 14–20% (women), but going too low harms hormones, immunity and durability. Treat these as ranges, not goals to undercut.
Why not just aim for a goal weight directly?
A goal weight says nothing about composition. If you lose muscle to hit it, you lose power and economy. Anchoring to lean mass keeps the loss where you want it — fat.
How fast can I safely reach race weight?
About 0.25–0.5 kg per week is the usual guidance so training quality and muscle are preserved. Aggressive deficits during heavy training tend to backfire.
Related calculators
Heart-rate and body-weight estimates are educational, based on population formulas — confirm with a coach or clinician before hard training, especially if you have any cardiac risk.