Sprocket: Bike Gear Calculator

Know your drivetrain before you ride. Live gear ratio, speed & gain ratio — fully offline, zero ads.

Stop guessing — know exactly what every gear combination delivers before you turn a pedal. Sprocket is the precise bike gear calculator built for road, gravel, MTB, and touring cyclists.

— KEY FEATURES —

• Live calculations: enter front chainring teeth, rear cog teeth, cadence (40–200 rpm), and wheel size — gear ratio, gain ratio, gear inches, and speed in km/h or mph update instantly as you type.

• Six wheel sizes: 700c, 650b/27.5", 29", 26", 24", and 20" — covers road, gravel, mountain, and kids' bikes.

• 10 built-in cassette presets: 11-speed road, gravel, and endurance; 10-speed touring and racing; 12-speed MTB wide-range — full cog-by-cog listings for every preset.

• Custom cassettes: add any cassette by entering a comma-separated cog sequence; the app auto-detects speed count and cog range.

• Saved bike setups: store named setups with chainring, cassette, wheel size, and target cadence. Each setup shows top speed, hardest gear ratio, gear inches, and easiest gear at a glance — perfect for comparing builds before swapping parts.

• 5 seeded setups to explore: Road Racer, Gravel Adventure, Trail MTB, Sprint Track, and Loaded Tourer — realistic starting points for every riding style.

• mph / km/h toggle: flip speed units anywhere in the app without re-entering data.

• Fully offline: no account, no ads, no network connection ever required. Your data lives on-device.

Whether you're speccing a new build, planning a gear swap, or nerding out on drivetrain math, Sprocket gives you the numbers you need — instantly and accurately.

— Sprocket Bike Gears PREMIUM —

Sprocket Premium unlocks the full app experience: unlimited saved bike setups, all 10 cassette presets plus custom cassette entry, and every calculation metric (gear ratio, gain ratio, gear inches, and speed) — completely ad-free and 100% offline.

Subscription options: • Weekly — $9.99 / week • Yearly — $49.99 / year (includes a 3-day free trial)

Payment is charged to your Apple Account at confirmation of purchase. Subscriptions renew automatically unless turned off at least 24 hours before the end of the current period. Your account is charged for renewal within 24 hours prior to the end of the period. Manage or cancel anytime in your Apple Account settings.

Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://pnkl26.web.app/privacy-policy