Observed arrival · 2026-10-03
Cycling Watts Calculator, with the Forces Left In
An interactive calculator estimates the power needed for a cycling speed, or the speed available at a given power, factoring in terrain, wind, aerodynamics, tires, and drivetrain.
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- For
- Cyclists estimating power or speed for specific ride conditions
- Worth noticing
- Riding-position CdA values range from 0.2914 for aerobars to 0.408 for tops, attributed to Jeukendrup (2002).
Field notes
The model expresses pedal power as the combined resisting forces multiplied by speed and adjusted for drivetrain efficiency. Its baseline tables assume an 8 kg road bike, hands on the hoods, standard wheels, race tires, a clean drivetrain, sea level, and no wind. The page also provides inputs for changing those conditions and cautions that real-world power can differ.
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Editorial observations of this landing page, not a rating.
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