# 235/55 R18

## What size is 235/55 R18?

235/55 R18 has an overall diameter of about 28.18 in, a section width of 9.25 in and a sidewall height of 5.09 in. It turns roughly 716 times per mile. Below are the exact figures plus in-tolerance plus/minus sizes you can switch to safely.

## Specification

| Specification | |
|---|---|
| Overall diameter | 28.18 in |
| Section width | 9.25 in |
| Sidewall height | 5.09 in |
| Circumference | 88.52 in |
| Revolutions | 445 /km · 716 /mi |

## In-tolerance sizes

| Size | Diameter | Speedo | Verdict |
|---|---|---|---|
| [235/50 R19](https://tirefitlab.com/235-50-r19.md) | +0.3% | +0.3% | ✓ OK |
| [235/60 R17](https://tirefitlab.com/235-60-r17.md) | -0.3% | -0.3% | ✓ OK |
| [255/45 R19](https://tirefitlab.com/255-45-r19.md) | -0.5% | -0.5% | ✓ OK |
| [235/65 R16](https://tirefitlab.com/235-65-r16.md) | -0.5% | -0.5% | ✓ OK |
| [255/35 R21](https://tirefitlab.com/255-35-r21.md) | -0.5% | -0.5% | ✓ OK |
| [215/65 R17](https://tirefitlab.com/215-65-r17.md) | -0.6% | -0.6% | ✓ OK |
| [225/65 R17](https://tirefitlab.com/225-65-r17.md) | +1.2% | +1.2% | ✓ OK |
| [225/55 R18](https://tirefitlab.com/225-55-r18.md) | -1.5% | -1.5% | ✓ OK |
| [275/40 R20](https://tirefitlab.com/275-40-r20.md) | +1.7% | +1.7% | ✓ OK |
| [245/45 R19](https://tirefitlab.com/245-45-r19.md) | -1.8% | -1.8% | ✓ OK |
| [245/45 R20](https://tirefitlab.com/245-45-r20.md) | +1.8% | +1.8% | ✓ OK |
| [275/40 R19](https://tirefitlab.com/275-40-r19.md) | -1.8% | -1.8% | ✓ OK |

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Methodology: https://tirefitlab.com/methodology/ · Tire size calculator: https://tirefitlab.com/235-55-r18/

> Geometry is computed in canonical millimetres and is deterministic across the site. Always verify physical clearance before fitting.