315/30 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 (315mm), which means the sidewall height has 94.5 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 295/30 R19
(2072.19 mm), 225/60 R15
(2045.18 mm), 295/45 R20
(2430.02 mm), 225/75 R16
(2337.03 mm), 325/30 R21
(2288.34 mm), 235/45 R18
(2100.78 mm), 235/55 R19
(2328.23 mm).
