Section Width305 mm (12.0")
Aspect Ratio14%
Rim Diameter21"
Overall Diameter619 mm (24.4")
Sidewall Height43 mm
Circumference1944 mm
305/14R21 — Buy Tires

Everything to know about the 305/14R21 tire size

Size geometry

A 305/14R21 tire has a 305mm section width and a 14% aspect ratio, mounted on a 21-inch rim. Sidewall height works out to 42.7mm (1.68") and overall outside diameter is 618.8mm (24.36"). At highway speed the tire completes about 514 revolutions per kilometre — your speedometer and odometer were calibrated against this number.

Direct substitute sizes

If 305/14R21 is unavailable, the closest same-diameter substitutes on the same rim are 295/14R21 and 315/14R21. 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 305/14R21 you can upsize to 315/10R22 (plus-one) to fit a larger wheel without changing the speedometer reading, or downsize to 295/19R20 (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 305/14R21 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 305/14R21

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