Tyre sizes·255/30R22
255/30R22
Overall diameter 711.8 mm

255/30R22 — 711.8 mm tall, and what it swaps with

255/30R22 is 255 mm wide with a 30% sidewall on a 22-inch wheel. That sidewall is 76.5 mm, so the tyre stands 711.8 mm tall and turns 447.2 times per kilometre.

Section width
255 mm
Aspect ratio
30 %
Wheel size
22 in (558.8 mm)
Sidewall height
76.5 mm
Overall diameter
711.8 mm (28.02 in)
Circumference
2236.2 mm
Turns per km
447.2

Sizes you can swap to

Only sizes whose overall diameter stays within 3% are listed. A different diameter covers a different distance per turn, and that gap becomes speedometer error.

Same profile, different width

Other sizes for this wheel

How the code reads

The 205 is millimetres, the 55 is a percentage of that width, and only the 16 is inches. The R stands for radial construction.

How to read this

  • The first three digits are the width in mm, the middle two are the aspect ratio in percent, the last two the wheel in inches.
  • Sidewall height = width × aspect ÷ 100. For 205/55 that is 112.75 mm.
  • Overall diameter = wheel diameter + twice the sidewall. A 16-inch wheel is 406.4 mm.
  • Once the diameter shifts by more than 3%, the speedometer and odometer drift by the same amount.

Frequently asked questions

Q. What is the overall diameter of 255/30R22?

711.8 mm — the 558.8 mm wheel plus the 76.5 mm sidewall at top and bottom.

Q. How many turns per kilometre does 255/30R22 make?

Its circumference is 2236.2 mm, so 447.2 turns.

Q. What can I swap it for?

12 sizes stay within 3% of its diameter — the closest is 255/35R21 at 711.9 mm.

Q. Why is the sidewall 76.5 mm?

Because it is 30% of the 255 mm width. The aspect ratio is a proportion of the width, not a length.