How to read a tyre size
Last updated: 25.09.2026
The tyre size is printed on the sidewall of every tyre, for example 205/55 R16 91V. The same size is listed in the vehicle registration document, on the sticker in the driver's door frame or fuel flap, and in the owner's manual. If in doubt, trust the door sticker: a previous owner may have fitted a different size.
What each number means
| Part | Example | Meaning |
|---|---|---|
| Width | 205 | Tread width in millimetres. A wider tyre has more contact area but also more rolling resistance and a higher price. |
| Profile | 55 | Sidewall height as a percentage of the width: 55 % of 205 mm is 113 mm. A lower profile steers more precisely, a higher one is more comfortable and tougher on potholes. |
| Construction | R | Radial construction. Practically all passenger car tyres are radial. ZR means the same with a speed rating above 240 km/h. |
| Diameter | 16 | Rim diameter in inches. The tyre must match the rim it will be mounted on exactly. |
| Load index | 91 | Maximum load per tyre: 91 = 615 kg. It must not be lower than the manufacturer's specification. |
| Speed index | V | Maximum speed: V = 240 km/h, H = 210, T = 190, W = 270. Winter tyres may have a lower rating than summer tyres if a sticker in the cabin says so. |
Common load and speed indexes
| Load | 82 = 475 kg | 87 = 545 kg | 91 = 615 kg | 94 = 670 kg | 98 = 750 kg | 104 = 900 kg |
|---|---|---|---|---|---|---|
| Speed | Q = 160 km/h | T = 190 | H = 210 | V = 240 | W = 270 | Y = 300 |
Can I fit a different size
Manufacturers usually approve several sizes for one car, for example 205/55 R16 and 225/45 R17: their outer diameter is almost identical, so the speedometer and ABS keep working correctly. The rule is simple: the outer diameter may differ by no more than 2 to 3 %, the load index must not be lower, and the tyre must fit the rim width. If you change the diameter, you change the rims too.
Always fit identical tyres on one axle: same size, model and wear. Put the newer or less worn pair on the rear axle so the rear does not slide out first.
Other sidewall markings
- DOT and production date, four digits: 2325 means week 23 of 2025. Tyres older than 6 years should be replaced regardless of tread depth.
- M+S and the snowflake symbol (3PMSF): 3PMSF is the real winter tyre mark; M+S alone does not make a winter tyre.
- XL or Reinforced: a reinforced tyre with a higher load index, needed for heavier cars and vans.
- Run Flat, RFT, SSR: a tyre you can drive on without pressure for a limited distance; not required unless the car came with them from the factory.
- TL means tubeless, which is every modern passenger car tyre.
Finding the tyre on our site
Enter the three numbers in the size finder at the top of the page or type them in any form, for example 2055516 or 205 55 16, the search understands both. Popular sizes: 205/55 R16, 195/65 R15, 225/45 R17, 215/60 R16. Every tyre also shows its EU label, which helps you compare more than the price.