Section Width175 mm (6.9")
Aspect Ratio103%
Rim Diameter21"
Overall Diameter894 mm (35.2")
Sidewall Height180 mm
Circumference2808 mm
175/103R21 — Buy Tires

Everything to know about the 175/103R21 tire size

Size geometry

A 175/103R21 tire has a 175mm section width and a 103% aspect ratio, mounted on a 21-inch rim. Sidewall height works out to 180.3mm (7.10") and overall outside diameter is 893.9mm (35.19"). At highway speed the tire completes about 356 revolutions per kilometre — your speedometer and odometer were calibrated against this number.

Direct substitute sizes

If 175/103R21 is unavailable, the closest same-diameter substitutes on the same rim are 165/109R21 and 185/97R21. 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 175/103R21 you can upsize to 185/91R22 (plus-one) to fit a larger wheel without changing the speedometer reading, or downsize to 165/117R20 (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 175/103R21 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 175/103R21

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