Section Width775 mm (30.5")
Aspect Ratio29%
Rim Diameter21"
Overall Diameter983 mm (38.7")
Sidewall Height225 mm
Circumference3088 mm
775/29R21 — Buy Tires

Everything to know about the 775/29R21 tire size

Size geometry

A 775/29R21 tire has a 775mm section width and a 29% aspect ratio, mounted on a 21-inch rim. Sidewall height works out to 224.8mm (8.85") and overall outside diameter is 982.9mm (38.70"). At highway speed the tire completes about 324 revolutions per kilometre — your speedometer and odometer were calibrated against this number.

Direct substitute sizes

If 775/29R21 is unavailable, the closest same-diameter substitutes on the same rim are 765/29R21 and 785/29R21. 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 775/29R21 you can upsize to 785/27R22 (plus-one) to fit a larger wheel without changing the speedometer reading, or downsize to 765/31R20 (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 775/29R21 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 775/29R21

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