180/55 R18 - Best winter tyres 2025 - market overview, tests, reviews

180/55 R18 doesn't belong to the most popular dimensions for winter tyres - there are 4 tyre models available, which can be compared to 155/60 R15, 170/60 R17, 160/60 R14. Let's break down the sizing - 55 is height of the tyre, which is calculated as 55% of the tyre width (180mm), which means the sidewall height has 99 mm. The wheel diameter is R18, which means it fits to a 18 inch/457.2mm diameter wheel. The total circumference of the tyre is 2058.37 mm, which is very similar to 245/30 R20(2057.74 mm), 295/25 R20(2059.31 mm), 160/70 R17(2060.26 mm), 245/35 R19(2054.92 mm), 195/70 R15(2054.6 mm), 225/55 R16(2054.29 mm), 285/35 R18(2063.08 mm). There are multiple speed indexes available for winter tyres in 180/55 R18: W(270km/h). The same goes for weight indexes: 74.