Section Width115 mm (4.5")
Aspect Ratio50%
Rim Diameter18"
Overall Diameter572 mm (22.5")
Sidewall Height58 mm
Circumference1798 mm
115/50R18 — Buy Tires

Everything to know about the 115/50R18 tire size

Size geometry

A 115/50R18 tire has a 115mm section width and a 50% aspect ratio, mounted on a 18-inch rim. Sidewall height works out to 57.5mm (2.26") and overall outside diameter is 572.2mm (22.53"). At highway speed the tire completes about 556 revolutions per kilometre — your speedometer and odometer were calibrated against this number.

Direct substitute sizes

If 115/50R18 is unavailable, the closest same-diameter substitutes on the same rim are 105/55R18 and 125/46R18. Both keep your speedometer reading within 1% — safe for daily use, ABS, and stability control. Always verify load and speed ratings before swapping.

Plus / minus sizing options

For a 115/50R18 you can upsize to 125/36R19 (plus-one) to fit a larger wheel without changing the speedometer reading, or downsize to 105/67R17 (minus-one) for a softer ride or winter setup. Both stay inside the Âą3% diameter tolerance that ABS and TPMS systems expect.

Vehicle compatibility

0 vehicles in our database run the 115/50R18 tire size from the factory. Aftermarket fitment depends on rim width, offset, and clearance — match these specs to your wheel before purchasing tires.

Vehicles Using 115/50R18

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