# 255/45 R18

## What size is 255/45 R18?

255/45 R18 has an overall diameter of about 27.04 in, a section width of 10.04 in and a sidewall height of 4.52 in. It turns roughly 746 times per mile. Below are the exact figures plus in-tolerance plus/minus sizes you can switch to safely.

## Specification

| Specification | |
|---|---|
| Overall diameter | 27.04 in |
| Section width | 10.04 in |
| Sidewall height | 4.52 in |
| Circumference | 84.93 in |
| Revolutions | 464 /km · 746 /mi |

## In-tolerance sizes

| Size | Diameter | Speedo | Verdict |
|---|---|---|---|
| [255/40 R19](https://tirefitlab.com/255-40-r19.md) | -0.0% | -0.0% | ✓ OK |
| [255/35 R20](https://tirefitlab.com/255-35-r20.md) | -0.0% | -0.0% | ✓ OK |
| [215/65 R16](https://tirefitlab.com/215-65-r16.md) | -0.1% | -0.1% | ✓ OK |
| [235/60 R16](https://tirefitlab.com/235-60-r16.md) | +0.2% | +0.2% | ✓ OK |
| [215/60 R17](https://tirefitlab.com/215-60-r17.md) | +0.5% | +0.5% | ✓ OK |
| [235/55 R17](https://tirefitlab.com/235-55-r17.md) | +0.5% | +0.5% | ✓ OK |
| [215/70 R15](https://tirefitlab.com/215-70-r15.md) | -0.7% | -0.7% | ✓ OK |
| [235/50 R18](https://tirefitlab.com/235-50-r18.md) | +0.8% | +0.8% | ✓ OK |
| [245/35 R20](https://tirefitlab.com/245-35-r20.md) | -1.0% | -1.0% | ✓ OK |
| [225/55 R17](https://tirefitlab.com/225-55-r17.md) | -1.1% | -1.1% | ✓ OK |
| [245/40 R19](https://tirefitlab.com/245-40-r19.md) | -1.2% | -1.2% | ✓ OK |
| [245/45 R18](https://tirefitlab.com/245-45-r18.md) | -1.3% | -1.3% | ✓ OK |

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Methodology: https://tirefitlab.com/methodology/ · Tire size calculator: https://tirefitlab.com/255-45-r18/

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