Cycling Wattage Calculator

Cycling wattage is the mechanical power you produce with your legs to propel your bike forward. It is measured in watts (W) and accounts for overcoming gravity, rolling resistance, and aerodynamic drag. It is widely regarded as the most accurate measure of cycling performance.

The total power is made up of three force components: gravity (Fg), rolling resistance (Fr), and aerodynamic drag (Fa). Each force is multiplied by your speed, and the result is divided by (1 − drivetrain loss) to give you the actual watts you need to produce at the pedals.

For a typical rider (75 kg) on a road bike in the hoods position on flat asphalt with no wind, you need roughly 200–230 watts to sustain 35 km/h. Wind, body position, and terrain can significantly change this figure.

Aerobars produce the lowest CdA (around 0.211 m²), making them the most aerodynamically efficient position. Drops and hoods follow, while the tops position has the highest drag. Switching from tops to aerobars can save 50–80 watts at the same speed.

Slick tires on smooth asphalt or concrete have the lowest rolling resistance, requiring less power. Knobby tires on grass or off-road terrain have much higher Crr values, meaning you need significantly more watts to maintain the same speed.

For recreational cyclists, 2–3 W/kg is typical. Trained club riders average 3–4 W/kg, while competitive amateur racers reach 4–5 W/kg. Elite professional cyclists can sustain over 6 W/kg for an hour during a race.

Sprint specialists can produce 1,500–2,000+ watts for a few seconds. For sustained efforts of 20 minutes to 1 hour, the range is roughly 250–450 W for trained riders, while world-class pros can hold 400–500+ W for an hour.

At higher elevations, air density (rho) is lower. This reduces aerodynamic drag, meaning you need fewer watts to maintain the same speed in still air. However, the effect is only significant above 1,500–2,000 metres.