🏎️ Tire Speed Calculator
Calculate vehicle speed based on tire diameter, gear ratio, and RPM
Tire Speed Calculator
Calculate vehicle speed based on tire diameter, gear ratio, and engine RPM
Common Tire Diameter Reference
Approximate overall diameters for common tire sizes
Street Tires
225/60R16: 26.6"
235/70R16: 28.0"
245/75R16: 29.5"
265/70R17: 30.6"
Performance
245/45R17: 25.7"
255/40R18: 26.0"
275/35R19: 26.6"
295/30R20: 27.0"
Drag Racing
28x9.0R15: 28.0"
29x10.5R15: 29.0"
30x12.0R15: 30.0"
31x13.5R15: 31.0"
Off-Road
31x10.5R15: 31.0"
33x12.5R15: 33.0"
35x12.5R17: 35.0"
37x13.5R17: 37.0"
How to Use
1. Enter tire diameter in inches
2. Input gear ratio (e.g., 3.73)
3. Enter engine RPM
4. View calculated speed in MPH
5. Compare different tire sizes and ratios
Features
✓ Larger tire diameter increases speed at same RPM
✓ Lower gear ratio increases speed but reduces acceleration
✓ Use for selecting optimal tire and gear combinations
✓ Consider transmission ratio for final calculations
✓ Account for tire wear affecting actual diameter