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Power to Speed Calculator — Estimate Speed from Watts

Estimate cycling speed from power output accounting for all resistances.

Hoods ~0.35, Drops ~0.32, TT ~0.24

Road tyre ~0.005


How We Calculate This

Speed from Power Formula

Total power is the sum of three resistance forces multiplied by speed:

  • Aerodynamic drag: P_aero = 0.5 x air density x CdA x v^3
  • Rolling resistance: P_roll = Crr x mass x g x v
  • Gravity: P_grav = mass x g x gradient x v

The calculator uses Newton-Raphson iteration to solve for speed where P_total = P_rider.

Frequently Asked Questions

Last updated: February 2026

All calculations are estimates. Always verify results and consult a professional bike fitter where appropriate.