Bike Gear Ratio Calculator

Chainring teeth divided by sprocket teeth. A 50-tooth chainring with an 11-tooth sprocket is 4.55, meaning the wheel turns 4.55 times per pedal revolution.

The wheel diameter a direct-drive penny-farthing would need to give the same development. It is why the numbers sit between about 20 and 130, and it survives purely by convention.

How far the bike travels per pedal revolution, in metres. It is the more intuitive measure and describes exactly the same thing as gear inches.

Most riders are efficient somewhere between 80 and 100 rpm, and trained cyclists often prefer higher. Very low cadences load the knees; very high ones raise heart rate without adding speed.

Enough to hold a comfortable cadence on the steepest climb and the fastest descent you ride. The range matters more than either extreme, since gaps between gears are what force you off your preferred cadence.

It gives a simpler system with wider gaps between gears for the same range. Whether that matters depends on whether you ride at a steady effort — road riders notice the gaps more than mountain bikers do.

Running the largest chainring with the largest sprocket, or the smallest with the smallest. The chain runs at an extreme angle, which wears it faster and is noisy — modern drivetrains tolerate it better than old ones.

By the terrain. A tight cassette keeps cadence steady on rolling ground; a wide one gives a climbing gear at the cost of larger jumps between gears.

Smaller chainrings, typically 50/34 rather than 53/39. It lowers every gear, which most riders benefit from far more than the top-end speed they lose.

One that lets you spin rather than grind on your steepest regular climb. A gear ratio near or below 1:1 is common on gravel and mountain bikes and increasingly on road bikes.

Yes — a larger wheel travels further per revolution, so the same gear ratio gives a higher effective gear. It is why 29-inch mountain bikes often use different cassettes from 27.5-inch ones.

Often 90 to 100 rpm on the flat and higher when accelerating, though preferences vary widely. Higher cadence shifts load from muscles to the cardiovascular system, which is the underlying trade.