Bike Gear Ratio & Cadence Speed Calculator
Figure out how fast a given gear combination will carry you at a chosen pedaling cadence, and see the resulting gear-inch value used by cyclists to compare gearing across bikes.
Speed
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Gear ratio—
Gear inches—
Speed (mph)—
Speed (km/h)—
About this calculator
Calculate your bicycle's speed from chainring/cog gear ratio, wheel size, and pedaling cadence.
Frequently Asked Questions
What is a gear ratio in cycling?
It's the number of chainring teeth divided by the number of rear cog teeth. A higher ratio means more distance covered per pedal revolution but more resistance.
What are gear inches?
Gear inches is a standardized way to compare gearing across different wheel sizes and drivetrains, calculated as gear ratio multiplied by wheel diameter.
Does this account for wind or terrain?
No, this is a theoretical speed based purely on gearing, wheel size, and cadence, assuming no slippage or resistance losses.