Interactive Tire Size Calculator
Compare two tire sizes side-by-side. See visual diameter overlays, speedometer calibration math, revs-per-mile differences, and fender clearance safety warnings instantly.
Popular Comparisons:
Tire 1 (Stock / Base)225/65R17
Overall Height:28.5"
Sidewall:5.8"
Revs/Mile:707
Tire 2 (New / Compare)245/60R18
Overall Height:29.6"
Sidewall:5.8"
Revs/Mile:682
Visual Tire & Wheel Comparison
Speedometer Variance
+3.7%At 60 mph reading, actual speed is 62.2 mph
| Indicated | Actual Speed | Diff |
|---|---|---|
| 20 mph | 20.7 mph | +0.7 mph |
| 30 mph | 31.1 mph | +1.1 mph |
| 45 mph | 46.7 mph | +1.7 mph |
| 60 mph | 62.2 mph | +2.2 mph |
| 75 mph | 77.8 mph | +2.8 mph |
| 90 mph | 93.3 mph | +3.3 mph |
Fender & Suspension Clearance
Fitment Status: MODERATE RISK
Flush fitment. Extends 17.7mm outwards. Check wheel arch clearance under full suspension compression.
Inner Strut Space:7.7mm LESS clearance
Outer Fender Push:Extends 17.7mm further out
Ride Height Delta:+0.53" ground clearance
How Tire Size Math Works
Tire sizes use a standard three-part format: [Section Width] / [Aspect Ratio] R [Rim Diameter] (e.g. 225/65R17).
- Section Width (225): The overall width of the tire from sidewall to sidewall in millimeters.
- Aspect Ratio (65): The sidewall height expressed as a percentage of the section width (65% of 225mm = 146.25mm sidewall height).
- Rim Diameter (R17): The wheel rim diameter in inches that the tire mounts on.
When changing tire sizes, keeping the overall diameter within ±3% of your vehicle's stock size ensures your speedometer remains accurate and prevents rubbing against suspension components or fender liners.