285/45 R20 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 - 45 is height of the tyre, which is calculated as 45% of the tyre width (285mm), which means the sidewall height has 128.25 mm. The wheel diameter is R20, which means it fits to a 20 inch/508mm diameter wheel. The total circumference of the tyre is mm, which is very similar to 215/60 R16
(2087.27 mm), 285/30 R20
(2133.14 mm), 215/75 R16
(2289.91 mm), 285/40 R20
(2312.21 mm), 225/45 R17
(1992.71 mm), 295/30 R18
(1992.4 mm), 225/55 R18
(2213.88 mm).
