235/70 R18 doesn't belong to the most popular dimensions for winter tyres - there are tyre models available, which can be compared to
325/30 R21,
155/60 R15,
155/65 R13. Let's break down the sizing - 70 is height of the tyre, which is calculated as 70% of the tyre width (235mm), which means the sidewall height has 164.5 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 mm, which is very similar to 265/70 R17
(2522.07 mm), 205/60 R16
(2049.58 mm), 275/35 R21
(2280.48 mm), 215/40 R17
(1896.89 mm), 275/45 R20
(2373.47 mm), 215/55 R17
(2099.53 mm), 285/25 R20
(2043.61 mm).
