155/85R18 vs 215/60R18
Compare overall diameter, sidewall height, width, circumference, and revs per mile for 155/85R18 and 215/60R18.
Fast facts
- 155/85R18: 28.37 in diameter
- 215/60R18: 28.16 in diameter
- Difference: -0.76%
Prefilled Comparison
Tire 1
Tire 2
Comparison Summary
| Measurement | 155/85R18 | 215/60R18 |
|---|---|---|
| Overall diameter (in) | 28.37 | 28.16 |
| Sidewall height (in) | 5.19 | 5.08 |
| Width (mm) | 155 | 215 |
| Circumference (in) | 89.14 | 88.46 |
| Revs per mile | 710.8 | 716.3 |
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How to read this comparison
This page compares 155/85R18 and 215/60R18 using the measurements that usually matter most: overall diameter, sidewall height, section width, circumference, and revolutions per mile. Diameter is the number to watch first because it changes how far the tire travels with each rotation.
If the second tire is taller, actual speed will usually be higher than the speed shown on the dashboard. If it is shorter, actual speed will usually be lower. The comparison table gives you a quick way to spot whether the change is small enough for your comfort or large enough that recalibration, gearing, or clearance deserves more attention.
Fitment is not just math. A size can be close in diameter and still rub because of width, wheel offset, suspension height, or steering angle. A size can also physically fit while creating more speedometer difference than you want. Use this comparison as the first filter, then verify load rating, wheel width, and clearance on the actual vehicle.
What changes between these sizes
Compared with 155/85R18, 215/60R18 is shorter the original size by about 0.22 inches, or -0.76%. That percentage is the quickest way to understand whether the swap is mild or meaningful. A small diameter change is usually easier to live with, while a larger change deserves more attention to speedometer accuracy and clearance.
The width changes by +60 mm, and the sidewall changes by about -0.11 inches. Those details matter for different reasons: width can affect clearance and stance, while sidewall height can affect ride feel and wheel protection. Overall diameter ties directly into actual road speed, revolutions per mile, and the way the vehicle feels at highway speeds.
If you are shopping between 155/85R18 and 215/60R18, use this page as the math check, not the final fitment approval. Tire brands, wheel width, offset, suspension setup, and vehicle load rating still need to line up. When in doubt, compare against the size listed on the vehicle placard and ask a tire professional to confirm the physical fit.