285/30 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 - 30 is height of the tyre, which is calculated as 30% of the tyre width (285mm), which means the sidewall height has 85.5 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 175/70 R13
(1807.04 mm), 255/35 R19
(2076.91 mm), 185/55 R14
(1756.46 mm), 255/45 R18
(2157.33 mm), 185/70 R14
(1930.82 mm), 255/60 R17
(2317.87 mm), 195/45 R16
(1828.09 mm).
