Sheldon Brown's		Gear Calculator

by Sheldon "Gain Ratio" Brown

New! Click here for a version for internal gear hubs

Wheel Size	27 inch (nominal) 26 inch (nominal) 700 X 44 / 44-622 700 X 38 / 38-622 700 X 35 / 35-622 700 X 32 / 32-622 700 X 28 / 28-622 700 X 25 / 25-622 700 X 23 / 23-622 700 X 20 / 20-622 Tubular / Wide Tubular / Narrow 27 X 1 3/8 / 35-630 27 X 1 1/4 / 32-630 27 X 1 1/8 / 28-630 27 X 1 / 25-630 26 X 2.125 / 54-559 / MTB 26 X 1.9 / 47-559 / MTB 26 X 1.5 / 38-559 / MTB 26 X 1.25 / 32-559 / MTB 26 X 1.0 / 25-559 / MTB 26 x 1/ 650C/ 25-571 26 X 1 3/8 / 35-590 24 inch (nominal) 24 x 1 / 25-520 20 inch (nominal) 20 X 1.75 / 44-406 / BMX 20 X 1 1/4 / 28-451 17 x 1 1/4 / 28-369 16 x 1 3/8 / 35-349
Crank Length	162.5 mm 165 mm 167.5 mm 170 mm 172.5 mm 175 mm 177.5 mm 180 mm
Gear units	Gain Ratios Gear inches Meters Developement MPH @ 40 RPM MPH @ 60 RPM MPH @ 80 RPM MPH @ 100 RPM MPH @ 120 RPM KPH @ 40 RPM KPH @ 60 RPM KPH @ 80 RPM KPH @ 100 RPM KPH @ 120 RPM
Chainrings
Stock Cassette	Custom Sizes 10-speed 13-14-15-16-17-19-21-23-26-29 10-speed 13-14-15-16-17-18-19-21-23-26 10-speed 12-13-14-15-16-17-19-21-23-25 10-speed 11-12-13-14-15-16-17-19-21-23 10-speed 11-12-13-14-15-16-17-18-19-21 9-speed "Century Special" 13-14-15-17-19-21-24-27-30 9-speed "Cyclotouriste" 13-15-17-19-21-24-27-30-34 9-speed 11-12-13-14-15-16-17-19-21 9-speed 12-13-14-15-16-17-18-19-21 9-speed 12-13-14-15-16-17-19-21-23 9-speed 11-12-13-14-15-17-19-21-23 9-speed 12-13-14-15-17-19-21-23-25 9-speed 12-13-14-15-17-19-21-24-27 9-speed 13-14-15-16-17-18-19-21-23 9-speed 13-14-15-16-17-19-21-23-25 9-speed 14-15-16-17-18-19-21-23-25 9-speed aq/ar 11-12-14-16-18-21-24-28-32 9-speed ap 12-14-16-18-20-23-26-30-34 9-speed as 11-13-15-17-20-23-26-30-34 8-speed "Megarange" 11-13-15-17-20-23-26-34 8-speed "ak/an" 11-13-15-17-20-23-26-30 8-speed "P" 12-14-16-18-21-24-28-32 8-speed "Q" 12-13-14-16-18-21-24-28 8-speed "R/ah" 11-12-14-16-18-21-24-28 8-speed "S" 12-13-14-15-16-17-19-21 8-speed "T" 13-14-15-16-17-19-21-23 8-speed "U" 12-13-14-15-17-19-21-23 8-speed "V" 13-14-15-17-19-21-23-26 8-speed "W" 12-13-15-17-19-21-23-25 7-speed "E" 12-14-16-18-21-24-28 7-speed "F" 14-16-18-21-24-28-32 7-speed "G" 13-15-17-20-23-26-30 7-speed "K" 13-15-17-20-24-29-34 7-speed "M" 13-15-17-19-21-24-28 7-speed "H" 13-15-17-19-21-23-26 7-speed "L" 12-13-14-15-17-19-21 7-speed "I" 13-14-15-17-19-21-23 7-speed "J" 13-14-15-16-17-19-21 7-speed "ab" 11-12-13-14-15-17-19 7-speed "ac" 11-13-15-18-21-24-28 7-speed "ai" 11-12-14-16-18-21-24 7-speed "am" 11-13-15-18-21-24-30
Custom Cassette
Internal Hub	----- No internal rear hub gears ----- SRAM/Sachs/Torpedo 3-speed, including 3 x 7 SRAM/Sachs/Torpedo 5-speed Shimano Nexus 4-speed Sturmey-Archer AB wide-ratio 3-speed w/brake Sturmey-Archer AC close-ratio 3-speed Sturmey-Archer AF close-ratio 4-speed Sturmey-Archer AM medium-ratio 3-speed Sturmey-Archer AG wide-ratio 3-speed w/dyno Sturmey-Archer AR ultra-close-ratio 3-speed Sturmey-Archer ASC fixed close-ratio 3-speed Sturmey-Archer AT3 wide-ratio 3-speed Sturmey-Archer AW wide-ratio 3-speed Sturmey-Archer AWC wide-ratio 3-speed w/coaster brake Sturmey-Archer FB wide-ratio 4-speed w/brake Sturmey-Archer FC close-ratio 4-speed Sturmey-Archer FG wide-ratio 4-speed w/dyno Sturmey-Archer FM medium-ratio 4-speed Sturmey-Archer FM modified to 5-speed Sturmey-Archer FW wide-ratio 4-speed Sturmey-Archer K, KB, KBC, KT, KTC wide-ratio 3-speed Sturmey-Archer KS close-ratio 3-speed Sturmey-Archer KSW medium-ratio 3-speed Sturmey-Archer S3C wide-ratio 3-speed w/coaster Sturmey-Archer SBR wide-ratio 3-speed w/brake Sturmey-Archer S5 5-speed Sturmey-Archer Sprinter 5-speed Sturmey-Archer SW super-wide-ratio 3-speed Sturmey-Archer T,TB,TBC,TBF,TBFC,TF wide-ratio 2-speed Sturmey-Archer TC close-ratio 2-speed Sturmey-Archer TCW wide-ratio 3-speed w/coaster

Gain Ratios	Gear Inches	Meters Development

If you want more numbers, including speed and cadence data,
Jake Odell has a more elaborate gear calculator:

HPV Drivetrain Analyzer

Thanks to Stephen D. Cohen and Timothy Lipetz for programming help

Feedback? Questions?

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