WheelPro Spoke Calculator is a spoke-length calculation tool for professional wheelbuilders, bicycle mechanics, and riders who build their own wheels.

Enter measured rim and hub dimensions to calculate each side independently and compare the calculated and recommended spoke lengths.

Key features

- Enter ERD, flange PCD, center-to-flange distance (FTC), and flange spoke-hole diameter
- Set left and right cross patterns and asymmetric rim offset
- Apply straight-pull spoke-hole offsets and nipple length adjustments
- Calculate standard J-bend and straight-pull wheels
- Support G3, G4, Triplet, PHH, PHR, and combined PHH+PHR lacing
- Compare calculated and recommended lengths for both sides
- Check left/right bracing angles and the estimated tension ratio in a true-scale axial view
- Save wheel builds and component records on your device
- Print results or save them as PDF or image; back up and restore builds with JSON files
- Use the interface in English, Korean, Japanese, Simplified Chinese, or German
- Use core calculation features offline after installation

Workshop-focused geometry

Enter the flange PCD, center-to-flange distance, and cross pattern separately for each side. This supports hubs with unequal left and right geometry, including disc-brake and rear hubs. Enter an asymmetric rim offset when the spoke-hole line is offset from the rim centerline.

Specialist lacing patterns

In addition to standard wheels, WheelPro supports G3, G4, Triplet, and paired-hole hub or rim layouts using PHH and PHR settings. The lacing preview is a visual aid for checking the selected inputs and pattern.

Axial view and tension ratio

The axial-offset zoom view draws both flanges and the rim at the same scale in both directions, shows the bracing angle of each side, and estimates the left/right tension ratio from the offsets and spoke lengths.

Records and export

Store frequently used rims, hubs, spokes, nipples, and wheel calculations on the device. Print the result, save it as a PDF or image, or move your builds between devices with JSON backup and restore.

Check before building

Results are theoretical values based on the dimensions and lacing conditions entered. Before ordering spokes or building a wheel, verify the rim and hub manufacturer's specifications, actual component dimensions, nipple engagement, and lacing instructions. Evaluate spoke tension with a calibrated tensiometer and the component manufacturer's permitted range.

WheelPro does not require an account. The app contains no third-party advertising or analytics SDK.