TireSize

205/45R17 Tire Size

205/45R17 diameter, sidewall, revolutions per mile, and plus-sizing options.

The 205/45R17 tire size breaks down as: 205 mm section width, 45% aspect ratio, and a 17-inch rim. Below are its real, calculated dimensions.

205/45R17 Calculated Dimensions

MetricValue
Overall diameter24.3 in (616 mm)
Sidewall height3.6 in (92 mm)
Circumference76.2 in (1936 mm)
Revolutions per mile831

Typical Fitment

205/45R17 is most often found on sport compacts. Always confirm against the door-jamb placard or owner manual before fitting.

Plus-Sizing Alternatives

These sizes keep the overall diameter close to 205/45R17, so speedometer and gearing stay near stock:

SizeDiameterDiameter change
215/45R1724.62 in+1.5%
215/35R1823.93 in-1.4%
225/30R1924.31 in+0.2%

Speedometer Note

If you fit a 215/45R17 instead of 205/45R17, the diameter changes by +1.5%. A taller tire makes your speedometer read low — at a true 60 mph it would show roughly 59 mph. A shorter tire has the opposite effect, so the gauge reads high.

Use the tire calculator to compare 205/45R17 against any other size and see the exact diameter and speedometer difference.

By Daniel Reyes, automotive editor

Frequently Asked Questions

What does 205/45R17 mean?

205/45R17 means a 205 mm wide tire with a 45% sidewall aspect ratio mounted on a 17-inch rim. The aspect ratio is the sidewall height as a percentage of the width.

Can I plus-size from 205/45R17?

Yes, as long as the replacement keeps the overall diameter close to stock so the speedometer stays accurate. Common plus-size moves from 205/45R17 are 215/45R17, 215/35R18, 225/30R19.

Will 205/45R17 affect my speedometer?

Only if it differs in diameter from your original size. A taller tire reads low; a shorter tire reads high. Compare the two sizes with the calculator to find the percentage.

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