Gear Ratio / RPM
RPM vs speed by tire + gearing.
HB Racing 7
10-Speed Transmission Ratio / RPM Calculator
Enter axle ratio, tire diameter, and up to 10 gear ratios. Then calculate road speed at RPM or RPM at road speed.
G1
G2
G3
G4
G5
G6
G7
G8
G9
G10
Tip: put your transmission ratios in order (1st → 10th). You can overwrite any gear.
Live results below. (Math updates instantly)
Results
Speed at 2000 RPM
| Gear | Gear Ratio | Speed (MPH) | Speed (km/h) |
|---|---|---|---|
| Gear 1 | 4.70 | 9.51 | 15.30 |
| Gear 2 | 2.98 | 14.99 | 24.13 |
| Gear 3 | 2.15 | 20.78 | 33.45 |
| Gear 4 | 1.77 | 25.24 | 40.63 |
| Gear 5 | 1.52 | 29.40 | 47.31 |
| Gear 6 | 1.28 | 34.91 | 56.18 |
| Gear 7 | 1.00 | 44.68 | 71.91 |
| Gear 8 | 0.85 | 52.57 | 84.60 |
| Gear 9 | 0.69 | 64.76 | 104.22 |
| Gear 10 | 0.63 | 70.93 | 114.14 |
Formulas: MPH = RPM × TireDia(in) ÷ (Gear × Axle × 336) and RPM = MPH × Gear × Axle × 336 ÷ TireDia(in).