Tyre sizes·265/50R20
265/50R20
Overall diameter 773 mm

265/50R20 — 773 mm tall, and what it swaps with

265/50R20 is 265 mm wide with a 50% sidewall on a 20-inch wheel. That sidewall is 132.5 mm, so the tyre stands 773 mm tall and turns 411.8 times per kilometre.

Section width
265 mm
Aspect ratio
50 %
Wheel size
20 in (508 mm)
Sidewall height
132.5 mm
Overall diameter
773 mm (30.43 in)
Circumference
2428.5 mm
Turns per km
411.8

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 265/50R20?

773 mm — the 508 mm wheel plus the 132.5 mm sidewall at top and bottom.

Q. How many turns per kilometre does 265/50R20 make?

Its circumference is 2428.5 mm, so 411.8 turns.

Q. What can I swap it for?

12 sizes stay within 3% of its diameter — the closest is 265/45R21 at 771.9 mm.

Q. Why is the sidewall 132.5 mm?

Because it is 50% of the 265 mm width. The aspect ratio is a proportion of the width, not a length.