SAPIM - Legacy Spoke calculator
Calculating spoke sizes the easy way
This tool will help you calculate the proper length for your spokes. Please select first your wheel type, then enter the appropriate values.
1Select your wheel type 
2Insert values
Fill in all variables to get the results
Left and right refers to the sides of the bike as you are riding it.
K = total axle length. Left/Right side = distance from hub centre to flange centre.
K = total hub length | flanges measured from centre
D = measured from the outside of one spoke hole to the outside of the opposite spoke hole on the flange.
D: outside of spoke hole → outside of opposite spoke hole
ERD = Effective Rim Diameter — the diameter at the point where spoke nipples seat.
Internal diameter (ERD)
Thickness of the rim wall where the spoke nipple seats.
Rim wall thickness
Missing values! Please correct the fields indicated in red.
3Results
Sapim cannot be held liable or responsible in respect of the use of this online calculator, data entered, nor for the results produced by any party using this online calculator, nor for any decisions taken based upon those results.