Section Width125 mm (4.9")
Aspect Ratio50%
Rim Diameter66"
Overall Diameter1801 mm (70.9")
Sidewall Height63 mm
Circumference5659 mm
125/50R66 — Buy Tires

Everything to know about the 125/50R66 tire size

Size geometry

A 125/50R66 tire has a 125mm section width and a 50% aspect ratio, mounted on a 66-inch rim. Sidewall height works out to 62.5mm (2.46") and overall outside diameter is 1801.4mm (70.92"). At highway speed the tire completes about 177 revolutions per kilometre — your speedometer and odometer were calibrated against this number.

Direct substitute sizes

If 125/50R66 is unavailable, the closest same-diameter substitutes on the same rim are 115/54R66 and 135/46R66. 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 125/50R66 you can upsize to 135/37R67 (plus-one) to fit a larger wheel without changing the speedometer reading, or downsize to 115/65R65 (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 125/50R66 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 125/50R66

tire_size.no_vehicles_found