Section Width125 mm (4.9")
Aspect Ratio378%
Rim Diameter37"
Overall Diameter1885 mm (74.2")
Sidewall Height473 mm
Circumference5921 mm
125/378R37 — Buy Tires

Everything to know about the 125/378R37 tire size

Size geometry

A 125/378R37 tire has a 125mm section width and a 378% aspect ratio, mounted on a 37-inch rim. Sidewall height works out to 472.5mm (18.60") and overall outside diameter is 1884.8mm (74.20"). At highway speed the tire completes about 169 revolutions per kilometre — your speedometer and odometer were calibrated against this number.

Direct substitute sizes

If 125/378R37 is unavailable, the closest same-diameter substitutes on the same rim are 115/411R37 and 135/350R37. 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 125/378R37 you can upsize to 135/341R38 (plus-one) to fit a larger wheel without changing the speedometer reading, or downsize to 115/422R36 (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 125/378R37 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 125/378R37

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