R2 GearCalc

Gear ratio calculator for drift and race cars. Pick your gearbox, final drive and tire size and instantly see: • wheel speed in every gear at your shift RPM • RPM drop on every upshift • a clear RPM vs speed sawtooth chart • speed per 1000 RPM for every gear WINTERS QUICK CHANGE BUILT IN The full Winters Performance 8500-series 10-spline gear chart is included: 67 spur gear sets with 4.12, 4.57 and 4.86 ring & pinion options. Ratios are computed from exact tooth counts. Star the sets you own to build your inventory and swap between them in one tap to compare setups. 269 GEARBOX PRESETS Factory ratio presets from popular manual and automatic transmissions (ZF GS6-53DZ selected by default), or enter a manual final drive ratio for any other setup. TIRE SIZE YOUR WAY Enter the outside diameter in millimeters or a metric size like 225/45R17, with common presets one tap away. BUILT FOR THE TRACK High-contrast dark interface with bright accents that stays readable in direct sunlight. No account, no ads, no data collection — everything stays on your device and works offline.