Race Weight Calculator

Race weight is the body weight you carry into a key event when your fat is low enough to help and your muscle is still intact. It matters because every extra kilo of fat costs you on climbs and over distance without giving anything back. The calculator above takes your current weight and body fat, holds your lean mass fixed, and shows the weight you would land at if you dropped to a target body-fat percent.

What the calculator works out

It treats your lean mass as a constant and only removes fat. Lower your body-fat target and the projected weight drops by exactly the fat you would shed. You feed it three numbers.

• Current weight: what you weigh today, ideally first thing in the morning.
• Current body-fat percent: from a DEXA scan, calipers, or a smart scale you trust for trends.
• Target body-fat percent: where you want to sit on race day.

The output is two figures: your projected race weight and the kilos of fat between you and that target.

Reading the result

The kilos-to-lose number sets your timeline. Aim for 0.25 to 0.5 kg of body weight per week. Faster than that and you start burning muscle alongside fat, which is the opposite of what you want. So a 4 kg gap is an 8 to 16 week project, not a six-week crash.

Hold a slow deficit and eat enough protein to protect lean mass: 1.6 to 2.2 g per kg of body weight per day. Keep training load steady. The deficit does the fat loss, the protein and the lifting keep the muscle.

The number is a ceiling, not a target

Race weight is the leanest you can be and still perform. It is not where you live year round. Push body fat too low and power drops, you get sick more often, and for some athletes hormones and bone health suffer. Women carry real risk here below roughly 12 percent, men below roughly 6 percent.

Treat the projected weight as the floor you touch for one peak, then let it come back up in the off-season. Chasing it for months is how athletes burn out and lose the muscle they spent years building.

For how to lose fat while holding muscle across a full block, read the body recomposition guide.