TireSize

325/60R20 Tire Size

325/60R20 diameter, sidewall, revolutions per mile, and plus-sizing options.

The 325/60R20 tire size breaks down as: 325 mm section width, 60% aspect ratio, and a 20-inch rim. Below are its real, calculated dimensions.

325/60R20 Calculated Dimensions

MetricValue
Overall diameter35.4 in (898 mm)
Sidewall height7.7 in (195 mm)
Circumference111.1 in (2821 mm)
Revolutions per mile570

Typical Fitment

325/60R20 is most often found on heavy-duty pickups. Always confirm against the door-jamb placard or owner manual before fitting.

Plus-Sizing Alternatives

These sizes keep the overall diameter close to 325/60R20, so speedometer and gearing stay near stock:

SizeDiameterDiameter change
335/60R2035.83 in+1.3%
335/55R2135.51 in+0.4%
345/50R2235.58 in+0.6%

Speedometer Note

If you fit a 335/60R20 instead of 325/60R20, the diameter changes by +1.3%. 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 325/60R20 against any other size and see the exact diameter and speedometer difference.

By Daniel Reyes, automotive editor

Frequently Asked Questions

What does 325/60R20 mean?

325/60R20 means a 325 mm wide tire with a 60% sidewall aspect ratio mounted on a 20-inch rim. The aspect ratio is the sidewall height as a percentage of the width.

Can I plus-size from 325/60R20?

Yes, as long as the replacement keeps the overall diameter close to stock so the speedometer stays accurate. Common plus-size moves from 325/60R20 are 335/60R20, 335/55R21, 345/50R22.

Will 325/60R20 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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