155/80 R12 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 - 80 is height of the tyre, which is calculated as 80% of the tyre width (155mm), which means the sidewall height has 124 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 155/60 R15
(1781.28 mm), 235/85 R16
(2531.81 mm), 160/60 R17
(1959.73 mm), 245/40 R19
(2131.88 mm), 165/70 R13
(1763.06 mm), 245/50 R19
(2285.82 mm), 175/65 R13
(1752.07 mm).
