Section Width125 mm (4.9")
Aspect Ratio278%
Rim Diameter12"
Overall Diameter1000 mm (39.4")
Sidewall Height348 mm
Circumference3141 mm
125/278R12 — Buy Tires

Everything to know about the 125/278R12 tire size

Size geometry

A 125/278R12 tire has a 125mm section width and a 278% aspect ratio, mounted on a 12-inch rim. Sidewall height works out to 347.5mm (13.68") and overall outside diameter is 999.8mm (39.36"). At highway speed the tire completes about 318 revolutions per kilometre — your speedometer and odometer were calibrated against this number.

Direct substitute sizes

If 125/278R12 is unavailable, the closest same-diameter substitutes on the same rim are 115/302R12 and 135/257R12. 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 125/278R12 you can upsize to 135/248R13 (plus-one) to fit a larger wheel without changing the speedometer reading, or downsize to 115/313R11 (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 125/278R12 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 125/278R12

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