275/30R21 Tire Size Specifications
This tire size 275/30R21 fits 1 vehicles in our database.
Everything to know about the 275/30R21 tire size
Size geometry
A 275/30R21 tire has a 275mm section width and a 30% aspect ratio, mounted on a 21-inch rim. Sidewall height works out to 82.5mm (3.25") and overall outside diameter is 698.4mm (27.50"). At highway speed the tire completes about 456 revolutions per kilometre â your speedometer and odometer were calibrated against this number.
Direct substitute sizes
If 275/30R21 is unavailable, the closest same-diameter substitutes on the same rim are 265/31R21 and 285/29R21. Both keep your speedometer reading within 1% â safe for daily use, ABS, and stability control. Always verify load and speed ratings before swapping.
Plus / minus sizing options
For a 275/30R21 you can upsize to 285/24R22 (plus-one) to fit a larger wheel without changing the speedometer reading, or downsize to 265/36R20 (minus-one) for a softer ride or winter setup. Both stay inside the Âą3% diameter tolerance that ABS and TPMS systems expect.
Vehicle compatibility
1 vehicles in our database run the 275/30R21 tire size from the factory. Aftermarket fitment depends on rim width, offset, and clearance â match these specs to your wheel before purchasing tires.