Section Width255 mm (10.0")
Aspect Ratio38%
Rim Diameter18"
Overall Diameter651 mm (25.6")
Sidewall Height97 mm
Circumference2045 mm
255/38R18 — Buy Tires

Everything to know about the 255/38R18 tire size

Size geometry

A 255/38R18 tire has a 255mm section width and a 38% aspect ratio, mounted on a 18-inch rim. Sidewall height works out to 96.9mm (3.81") and overall outside diameter is 651.0mm (25.63"). At highway speed the tire completes about 489 revolutions per kilometre — your speedometer and odometer were calibrated against this number.

Direct substitute sizes

If 255/38R18 is unavailable, the closest same-diameter substitutes on the same rim are 245/40R18 and 265/37R18. 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 255/38R18 you can upsize to 265/32R19 (plus-one) to fit a larger wheel without changing the speedometer reading, or downsize to 245/45R17 (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 255/38R18 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 255/38R18

tire_size.no_vehicles_found