Section Width945 mm (37.2")
Aspect Ratio27%
Rim Diameter21"
Overall Diameter1044 mm (41.1")
Sidewall Height255 mm
Circumference3279 mm
945/27R21 — Buy Tires

Everything to know about the 945/27R21 tire size

Size geometry

A 945/27R21 tire has a 945mm section width and a 27% aspect ratio, mounted on a 21-inch rim. Sidewall height works out to 255.2mm (10.05") and overall outside diameter is 1043.7mm (41.09"). At highway speed the tire completes about 305 revolutions per kilometre — your speedometer and odometer were calibrated against this number.

Direct substitute sizes

If 945/27R21 is unavailable, the closest same-diameter substitutes on the same rim are 935/27R21 and 955/27R21. 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 945/27R21 you can upsize to 955/25R22 (plus-one) to fit a larger wheel without changing the speedometer reading, or downsize to 935/29R20 (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 945/27R21 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 945/27R21

tire_size.no_vehicles_found