145/70 R12 doesn't belong to the most popular dimensions for summer 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 (145mm), which means the sidewall height has 101.5 mm. The wheel diameter is R12, which means it fits to a 12 inch/304.8mm diameter wheel. The total circumference of the tyre is mm, which is very similar to 185/70 R14
(1930.82 mm), 255/60 R17
(2317.87 mm), 195/45 R16
(1828.09 mm), 265/30 R20
(2095.44 mm), 195/60 R16
(2011.88 mm), 265/40 R18
(2102.35 mm), 195/80 R15
(2177.12 mm).
