// Bicycle Gear Calculator v2.0

Calculate your perfect drivetrain

Advanced gear development, speed, and cadence calculator for gravel cyclists and bikepackers. Visualize your entire cassette range.

// Drivetrain Setup Configure your bike
Preset:
90 rpm
25 km/h
Speed
—
km/h @ selected gear
Development
—
meters/rev
Gain ratio
—
gear ratio
Cadence needed
—
rpm for target speed
Gear Matrix
Visual Chart
Speed Table
Click any cell to select that gear combination. Green = easy/climbing, orange = mid-range, red = fast/hard. Values shown in km/h at current cadence.
Development in meters per pedal revolution. Longer bar = higher gear. Click a bar to select that gear.
Full speed table for all gear combinations at current cadence. Ratio = chainring ÷ sprocket. Dev. = development in meters.
// About Gear Calculations

Gear Development

Development (or rollout) is the distance your bike travels with one full pedal revolution. Calculated as: (chainring ÷ sprocket) × wheel circumference. Gravel bikes typically range from 1.5m (climbing) to 9m+ (sprinting).

Speed Formula

Speed = Development × Cadence × 60 ÷ 1000. At 90 rpm with a 6m development, you're doing 32.4 km/h. For bikepacking, most riders spin 70-90 rpm and target 20-30 km/h average on mixed terrain.