Every watt
counts.

Divide power in watts by rider weight in kilograms: W/kg = watts ÷ kilograms. For example, 300 W divided by 80 kg is 3.75 W/kg. Enter your numbers in the W/kg calculator to see the result instantly. Use power from the same effort duration when comparing two rides or riders.

Convert pounds to kilograms by multiplying pounds by 0.45359237, then divide watts by that result. A 165 lb rider weighs about 74.84 kg; at 250 W, that is about 3.34 W/kg. Select “lbs” in the calculator and the conversion happens automatically.

There isn’t one universal “good” number. Training background, effort duration and testing conditions all affect the result. TrainerRoad’s approximate beginner racing ranges are 2.4–3.1 W/kg for men and 1.9–2.6 W/kg for women at FTP. These describe a racing reference, not a requirement for enjoying cycling. The benchmark chart shows the wider context.

At FTP, 3 W/kg overlaps TrainerRoad’s beginner and Cat 4 men’s ranges, and Cat 4 and Cat 3 women’s ranges. At 4 W/kg, the overlaps shift to Cat 3 and Cat 2 for men, and the Cat 2 range for women. These are approximate references: fitness, handling, endurance and race tactics all contribute to performance.

Multiply your weight in kilograms by four. At 60 kg, 4 W/kg requires 240 W; at 75 kg, it requires 300 W; at 90 kg, it requires 360 W. Use the what-if lab to calculate a target at your own weight. The result is the power required mathematically, not a prediction of your training progress.

Standard rider W/kg uses your body weight only. For climbing physics, the bike, clothing, bottles and equipment also have to move uphill. That is why the climb simulator adds an assumed 8 kg for the bike and kit. Its speed estimate uses total mass, while your headline W/kg uses rider mass.

No. FTP is an estimate of sustained threshold power. A common field-test method takes 95% of a properly paced 20-minute test, but that relationship varies between riders and protocols. If your test averaged 260 W, this method gives an estimated FTP of 247 W. Use an FTP estimate from a consistent testing method, rather than entering raw 20-minute power as FTP. Read CTS’s guide to FTP testing ↗

Equal rider W/kg can mean very different absolute power. At 3 W/kg, a 60 kg rider produces 180 W and a 90 kg rider produces 270 W. On flat roads, aerodynamic drag matters greatly and does not scale directly with body weight. Rider position, equipment, drafting and conditions can outweigh differences in W/kg.

The zones here use a continuous interpretation of Coggan’s power levels: recovery up to 55% of FTP, endurance above 55–75%, tempo above 75–90%, threshold above 90–105%, VO₂ max above 105–120%, and anaerobic efforts above 120%. Neuromuscular sprint power has no fixed FTP percentage. Rounded watt ranges are shown in your power zones.

The ratio itself is straightforward arithmetic. Speed is an estimate because it also depends on gradient, total weight, air resistance, road surface, wind and drivetrain losses. Our simulator assumes a steady grade and constant FTP. It excludes corners, braking and fatigue, so use it to compare scenarios rather than predict a finish time.

Yes. At the same body weight, producing more power increases W/kg. Moving from 250 W to 275 W at 75 kg changes the ratio from 3.33 to 3.67 W/kg, a 10% increase. The what-if lab keeps weight constant so you can explore the effect of power improvements.

Your inputs are saved in this browser’s local storage. This app has no account system or analytics and does not send calculator inputs to an application backend. “Share result” puts your selected power, weight, effort and FTP in a link’s fragment, so anyone you give that link to can see those numbers. Standard web-server access logs may still record page visits.