Wheelbuilding and Spoke Calculators
FreeSpoke
Thinking of building some wheels? FreeSpoke is a powerful spoke length calculator with a user-updatable database of rim and hub measurements.
Spoke tension balancing utility
Inspired by the Park Tool TCC spreadsheet, but more powerful, web-based, and compatible with several different tensiometers. Use this utility to help balance the tension of your wheels.
Gear Calculators
Visual calculator and drivetrain comparison tool
New! Compare any two bicycle drivetrains side-by-side in graph format. Supports many internally-geared hubs.
Fixed gear visual calculator
This calculator uses the same visual style of the main calculator, but has added features for fixed gear applications. (in progress)
SS/FG gear calculator
The original kstoerz calculator. This provides a unique way to compare and select gear ratios for singlespeed and fixed gear drivetrains.
Other Stuff
Ruler Tool
Display distance values in various units on an inch or foot ruler.