Section Width125 mm (4.9")
Aspect Ratio40%
Rim Diameter20"
Overall Diameter608 mm (23.9")
Sidewall Height50 mm
Circumference1910 mm
125/40R20 — Buy Tires

Everything to know about the 125/40R20 tire size

Size geometry

A 125/40R20 tire has a 125mm section width and a 40% aspect ratio, mounted on a 20-inch rim. Sidewall height works out to 50.0mm (1.97") and overall outside diameter is 608.0mm (23.94"). At highway speed the tire completes about 524 revolutions per kilometre — your speedometer and odometer were calibrated against this number.

Direct substitute sizes

If 125/40R20 is unavailable, the closest same-diameter substitutes on the same rim are 115/43R20 and 135/37R20. 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 125/40R20 you can upsize to 135/28R21 (plus-one) to fit a larger wheel without changing the speedometer reading, or downsize to 115/55R19 (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 125/40R20 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 125/40R20

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