265/35 R18 doesn't belong to the most popular dimensions for 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 - 35 is height of the tyre, which is calculated as 35% of the tyre width (265mm), which means the sidewall height has 92.75 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 215/35 R18
(1909.15 mm), 275/45 R19
(2293.68 mm), 215/50 R18
(2111.78 mm), 275/70 R16
(2486.26 mm), 215/65 R17
(2234.61 mm), 285/35 R21
(2302.47 mm), 225/35 R19
(2010.93 mm).