Bicycle Gear Ratio & Speed Chart
Your gear ratio determines how far you travel with each pedal revolution and directly affects the speed you can maintain at a given cadence. This reference covers common road and MTB drivetrains, gear inches and the speed you'll achieve at a typical 90 rpm cadence.
Understanding Gear Ratio
Gear Ratio = Chainring teeth ÷ Cassette teeth
Gear Inches = Gear Ratio × Wheel diameter (inches)
Development = Gear Ratio × Wheel circumference (metres) — distance per pedal revolution
Speed at cadence = Development × Cadence × 60 ÷ 1000 (km/h)
Road Bike — 50/34 Chainset with 11–28 Cassette
A standard compact road setup (700c wheel, 25 mm tyre, 2.136 m circumference).
| Chainring | Cassette | Ratio | Gear Inches | Development (m) | Speed @ 90 rpm |
|---|---|---|---|---|---|
| 34 | 28 | 1.21 | 32.8 | 2.59 | 14.0 km/h |
| 34 | 25 | 1.36 | 36.7 | 2.91 | 15.7 km/h |
| 34 | 21 | 1.62 | 43.7 | 3.46 | 18.7 km/h |
| 34 | 17 | 2.00 | 54.0 | 4.27 | 23.1 km/h |
| 50 | 28 | 1.79 | 48.2 | 3.81 | 20.6 km/h |
| 50 | 21 | 2.38 | 64.3 | 5.09 | 27.5 km/h |
| 50 | 15 | 3.33 | 90.0 | 7.12 | 38.4 km/h |
| 50 | 11 | 4.55 | 122.7 | 9.71 | 52.4 km/h |
Mountain Bike — 32T Chainring with 10–52 Cassette
A typical 1×12 MTB setup (29″ wheel, 2.3″ tyre, 2.295 m circumference).
| Chainring | Cassette | Ratio | Gear Inches | Development (m) | Speed @ 90 rpm |
|---|---|---|---|---|---|
| 32 | 52 | 0.62 | 17.8 | 1.41 | 7.6 km/h |
| 32 | 42 | 0.76 | 22.1 | 1.75 | 9.4 km/h |
| 32 | 28 | 1.14 | 33.1 | 2.62 | 14.2 km/h |
| 32 | 18 | 1.78 | 51.5 | 4.08 | 22.0 km/h |
| 32 | 14 | 2.29 | 66.2 | 5.24 | 28.3 km/h |
| 32 | 10 | 3.20 | 92.7 | 7.34 | 39.6 km/h |
Common Drivetrain Configurations
| Type | Chainring(s) | Cassette Range | Gear Range (%) |
|---|---|---|---|
| Road 2×11 | 50/34 | 11–28 | 467% |
| Road 2×12 | 50/34 | 11–34 | 555% |
| Gravel 1×12 | 40 | 10–44 | 440% |
| Gravel 2×11 | 46/30 | 11–36 | 502% |
| MTB 1×12 | 32 | 10–52 | 520% |
Related Calculators
- Gearing Calculators — calculate gear ratios, gear inches and speed for your exact setup
Wheel circumferences used: 700c × 25 mm = 2.136 m; 29″ × 2.3″ = 2.295 m. Actual circumference varies with tyre brand, pressure and load. Speed figures assume a flat road with no wind resistance — real-world speed will be lower.