255/75 R16 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 - 75 is height of the tyre, which is calculated as 75% of the tyre width (255mm), which means the sidewall height has 191.25 mm. The wheel diameter is R16, which means it fits to a 16 inch/406.4mm diameter wheel. The total circumference of the tyre is mm, which is very similar to 275/40 R21
(2366.88 mm), 215/45 R18
(2044.23 mm), 275/55 R19
(2466.46 mm), 215/65 R15
(2075.02 mm), 285/35 R18
(2063.08 mm), 215/85 R16
(2425 mm), 285/45 R19
(2321.95 mm).
