Section Width945 mm (37.2")
Aspect Ratio12%
Rim Diameter31"
Overall Diameter1014 mm (39.9")
Sidewall Height113 mm
Circumference3186 mm
945/12R31 — Buy Tires

Everything to know about the 945/12R31 tire size

Size geometry

A 945/12R31 tire has a 945mm section width and a 12% aspect ratio, mounted on a 31-inch rim. Sidewall height works out to 113.4mm (4.46") and overall outside diameter is 1014.2mm (39.93"). At highway speed the tire completes about 314 revolutions per kilometre — your speedometer and odometer were calibrated against this number.

Direct substitute sizes

If 945/12R31 is unavailable, the closest same-diameter substitutes on the same rim are 935/12R31 and 955/12R31. 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 945/12R31 you can upsize to 955/11R32 (plus-one) to fit a larger wheel without changing the speedometer reading, or downsize to 935/13R30 (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 945/12R31 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 945/12R31

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