🛞 Tire Calculator
Calculate tire diameter effects on speed and performance
🛞 Original Tire Size
225/60R16
Diameter: 26.6"
🛞 New Tire Size
245/50R17
Diameter: 26.6"
Size Comparison Results
+0.02"
Diameter Difference
+0.1%
Percentage Change
0.05"
Circumference Difference
Speedometer Accuracy
Note: Larger tires make your speedometer read slower than actual speed. Smaller tires make it read faster than actual speed.
Common Tire Size Examples
Compact Cars
185/65R1524.5"
195/60R1624.2"
205/55R1624.9"
Mid-Size Cars
215/60R1626.2"
225/55R1726.7"
235/50R1827.3"
Performance Cars
245/40R1825.7"
275/35R1926.6"
295/30R2027.0"
SUVs/Trucks
235/75R1528.9"
265/70R1731.6"
285/75R1632.8"
Off-Road
31x10.50R1531.0"
33x12.50R1533.0"
35x12.50R1735.0"
Plus Sizing
225/60R1626.6" (Original)
225/50R1726.9" (+1)
225/45R1826.0" (+2)
Calculation Formula
Tire Diameter Calculation:
Diameter = Rim Diameter + (2 × Sidewall Height)
Sidewall Height = (Tire Width × Aspect Ratio) ÷ 100 ÷ 25.4
Speed Correction:
Actual Speed = Speedometer Reading × (New Diameter ÷ Original Diameter)
Important: Changing tire size affects speedometer accuracy, fuel economy, and vehicle performance. Most manufacturers recommend staying within ±3% of the original tire diameter.
How to Use
1. Enter original tire size (width/aspect/rim)
2. Input new tire size for comparison
3. View speed and RPM differences
4. Analyze performance impact
Features
✓ Tire size comparison
✓ Speed difference calculation
✓ RPM change analysis
✓ Performance impact assessment