235/55R18 refers to the size of the tire. It’s a standard which is used by car and tire manufacturers. By having the standard, tire manufacturers are able to manufacture same size tires independently and users can buy same size tires from different manufacturers.
Here’s an explanation of what these metrics mean in practice:
| 235 | The tire width is 235mm. |
| 55 | The aspect ratio of the tire is 55. Aspect ratio refers to the height of tire sidewall in relation to tire width in percentages. |
| R | The letter in the middle refers to tire construction. Practically all tires sold for cars are radials. Sometimes you also see tires with RF or ZR. RF indicates the tire is run flat, whereas ZR means the tire has speed rating higher than V. These tires are also radials, as the R indicates. |
| 18 | Rim diameter for the tire. 235/55R18 tire can be mounted only to a 18″ rims. |
Best selling 235/55R18 tires
Summit Ultramax A/S All-Season Tire - 235/55R18 100V
(as of June 2, 2023 15:42 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)
Set of 4 (FOUR) Fullway HP108 All-Season High Performance Radial Tires-235/55R18 235/55ZR18 235/55/18 235/55-18 104W Load Range XL 4-Ply BSW Black Side Wall
(as of June 2, 2023 15:42 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)
Evoluxx Capricorn 4X4 HP All-Season Performance Radial Tire-235/55R18 235/55/18 235/55-18 104V Load Range XL 4-Ply BSW Black Side Wall
14% Off(as of June 2, 2023 15:42 GMT +00:00 - More infoProduct prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on [relevant Amazon Site(s), as applicable] at the time of purchase will apply to the purchase of this product.)
What is 235/55R18 tire size in inches?
Because the width of 235/55R18 tire is stated in millimeters and sidewall height in percentages, you have to make calculations to see what the true size of 235/55R18 is in inches. Luckily, we have made these calculations for you.In this table you can see size of 235/55R18 in inches, as well as few additional metrics:
| In inches | In millimeters | |
| Section Width | 9.3″ | 235mm |
| Sidewall height | 5.1″ | 129mm |
| Diameter / Height | 28.2″ | 716mm |
| Circumference | 88.5″ | 2248mm |
| Rim Diameter | 18″ | |
| Revolutions | 716 per mile | 445 per kilometer |
Recommended Rim Sizes for 235/55R18 Tires
For 235/55R18 tires you need to have correct size rims to install the tires to. There are different width rims available in the market, and you can run into problems by installing 235/55R18 to a too wide or too narrow rim. Here are the recommended rim sizes for 235/55R18 tire:
| Diameter | Width Range |
| 18″ | 6.5-8.5″ |
235/55R18 – Variations
When you look at the tire code on 235/55R18 tires, you may see there are additional numbers and letters after the code 235/55R18. These numbers and letters refer to speed rating and load index of the tire. 235/55R18 has at least following variations available on the markets:
235/55R18 99H 235/55R18 100H 235/55R18 100S 235/55R18 100T 235/55R18 100V 235/55R18 100W 235/55R18 104H 235/55R18 104T 235/55R18 104V 235/55R18 104W