Section Width125 mm (4.9")
Aspect Ratio500%
Rim Diameter21"
Overall Diameter1783 mm (70.2")
Sidewall Height625 mm
Circumference5603 mm
125/500R21 — Buy Tires

Everything to know about the 125/500R21 tire size

Size geometry

A 125/500R21 tire has a 125mm section width and a 500% aspect ratio, mounted on a 21-inch rim. Sidewall height works out to 625.0mm (24.61") and overall outside diameter is 1783.4mm (70.21"). At highway speed the tire completes about 178 revolutions per kilometre — your speedometer and odometer were calibrated against this number.

Direct substitute sizes

If 125/500R21 is unavailable, the closest same-diameter substitutes on the same rim are 115/543R21 and 135/463R21. 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 125/500R21 you can upsize to 135/454R22 (plus-one) to fit a larger wheel without changing the speedometer reading, or downsize to 115/555R20 (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 125/500R21 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 125/500R21

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