Section Width135 mm (5.3")
Aspect Ratio37%
Rim Diameter21"
Overall Diameter633 mm (24.9")
Sidewall Height50 mm
Circumference1990 mm
135/37R21 — Buy Tires

Everything to know about the 135/37R21 tire size

Size geometry

A 135/37R21 tire has a 135mm section width and a 37% aspect ratio, mounted on a 21-inch rim. Sidewall height works out to 50.0mm (1.97") and overall outside diameter is 633.3mm (24.93"). At highway speed the tire completes about 503 revolutions per kilometre — your speedometer and odometer were calibrated against this number.

Direct substitute sizes

If 135/37R21 is unavailable, the closest same-diameter substitutes on the same rim are 125/40R21 and 145/34R21. 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 135/37R21 you can upsize to 145/26R22 (plus-one) to fit a larger wheel without changing the speedometer reading, or downsize to 125/50R20 (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 135/37R21 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 135/37R21

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