Tyre sizes·205/50R17
205/50R17
Overall diameter 636.8 mm

205/50R17 — 636.8 mm tall, and what it swaps with

205/50R17 is 205 mm wide with a 50% sidewall on a 17-inch wheel. That sidewall is 102.5 mm, so the tyre stands 636.8 mm tall and turns 499.9 times per kilometre.

Section width
205 mm
Aspect ratio
50 %
Wheel size
17 in (431.8 mm)
Sidewall height
102.5 mm
Overall diameter
636.8 mm (25.07 in)
Circumference
2000.6 mm
Turns per km
499.9

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 205/50R17?

636.8 mm — the 431.8 mm wheel plus the 102.5 mm sidewall at top and bottom.

Q. How many turns per kilometre does 205/50R17 make?

Its circumference is 2000.6 mm, so 499.9 turns.

Q. What can I swap it for?

12 sizes stay within 3% of its diameter — the closest is 225/40R18 at 637.2 mm.

Q. Why is the sidewall 102.5 mm?

Because it is 50% of the 205 mm width. The aspect ratio is a proportion of the width, not a length.