Section Width725 mm (28.5")
Aspect Ratio18%
Rim Diameter21"
Overall Diameter794 mm (31.3")
Sidewall Height131 mm
Circumference2496 mm
725/18R21 — Buy Tires

Everything to know about the 725/18R21 tire size

Size geometry

A 725/18R21 tire has a 725mm section width and a 18% aspect ratio, mounted on a 21-inch rim. Sidewall height works out to 130.5mm (5.14") and overall outside diameter is 794.4mm (31.28"). At highway speed the tire completes about 401 revolutions per kilometre — your speedometer and odometer were calibrated against this number.

Direct substitute sizes

If 725/18R21 is unavailable, the closest same-diameter substitutes on the same rim are 715/18R21 and 735/18R21. 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 725/18R21 you can upsize to 735/16R22 (plus-one) to fit a larger wheel without changing the speedometer reading, or downsize to 715/20R20 (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 725/18R21 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 725/18R21

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