Bike Gradient Power Calculator

Ride inputs

Speed km/h

Gradient %

Total weight (rider + bike + gear) kg

Aerodynamics

Riding position

Drag area, CdA m²

Wind speed km/h, headwind +

Rolling resistance

Surface / tyres

Rolling resistance coefficient, Crr

Air & drivetrain

Altitude m

Air temperature °C

Drivetrain efficiency %

Result

Component	Force (N)	Power (W)

Graph

Power vs gradient (at this speed) Power vs speed (at this gradient)

How this was calculated

This uses the standard cycling physics model (gravity + rolling resistance + aerodynamic drag, scaled up for drivetrain loss). It's my best estimate of the formula from your spreadsheet — swap in calculatePower() in app.js once the real spreadsheet formula is available.