Bicycle Power Calculator Bicycle Power Calculator
Constant speed analysis
Drag coefficients reference "Science of Cycling", E.R. Burke, Leisure Press, 1986, pg 126.

Wheel Diameter (inches)        Crank Length (inches)
Desired Constant Speed (mph)       Rider's Weight (lbs)       Bicycle Weight (lbs)
% Grade (+ for uphill,- for downhill)       Mechanical Losses (3-5% is typical) %
Gear Ratio (#Teeth Rear/Front)            
Air Resistance Coefficient (lbf*s^2/ft^2) = Cd*FrontalArea
Rolling Resistance Coefficient (lbf/lbf)       

Calculated Outputs
Total required input power from the rider       HP     Watts
Power needed to overcome air resistance      HP   %
Power to overcome rolling resistance in tires  HP   %
Power needed for elevation change               HP   %
Power lost to mechanical losses, friction, etc. HP   %
    Calories burned per mile kcals (assuming 28% efficiency in conversion to human power output)
    Average Pedal Force Lbs     Average Traction Force Lbs
    Pedal Speed RPM                Tire Speed RPM

You are visitor # since 14 March 2005

copyright 1999 Penn State      19 August 2005 by John S. Lamancusa - Penn State University (
Accuracy checked by ME288 Product Dissection class, Underlying Equations