205/70R15
Overall diameter 668 mm
205/70R15 — 668 mm tall, and what it swaps with
205/70R15 is 205 mm wide with a 70% sidewall on a 15-inch wheel. That sidewall is 143.5 mm, so the tyre stands 668 mm tall and turns 476.5 times per kilometre.
- Section width
- 205 mm
- Aspect ratio
- 70 %
- Wheel size
- 15 in (381 mm)
- Sidewall height
- 143.5 mm
- Overall diameter
- 668 mm (26.3 in)
- Circumference
- 2098.6 mm
- Turns per km
- 476.5
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.
265/35R19668.1 mm · +0.01% you go faster215/55R17668.3 mm · +0.04% you go faster235/45R18668.7 mm · +0.1% you go faster265/30R20667 mm · -0.15% you go slower235/40R19670.6 mm · +0.39% you go faster215/60R16664.4 mm · -0.54% you go slower215/50R18672.2 mm · +0.63% you go faster235/35R20672.5 mm · +0.67% you go faster205/65R16672.9 mm · +0.73% you go faster275/30R20673 mm · +0.75% you go faster225/40R19662.6 mm · -0.81% you go slower255/40R18661.2 mm · -1.02% you go slower
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 205/70R15?
668 mm — the 381 mm wheel plus the 143.5 mm sidewall at top and bottom.
Q. How many turns per kilometre does 205/70R15 make?
Its circumference is 2098.6 mm, so 476.5 turns.
Q. What can I swap it for?
12 sizes stay within 3% of its diameter — the closest is 265/35R19 at 668.1 mm.
Q. Why is the sidewall 143.5 mm?
Because it is 70% of the 205 mm width. The aspect ratio is a proportion of the width, not a length.