SprocketMath is a small set of free calculators for people who change sprockets and chains themselves – dirt bike and pit bike riders, ATV owners and go-kart builders.
How the numbers are worked out
Every calculator runs in your browser using the standard formulas, written out on each page so you can check them by hand. Chain dimensions follow the ANSI roller chain standard and the common motorcycle chain sizes. Results are theoretical: real top speed depends on power, weight and tire slip.
Found a mistake?
Please get in touch – corrections are fixed quickly and make the site better for everyone.