215/75 R15 doesn't belong to the most popular dimensions for winter 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 (215mm), which means the sidewall height has 161.25 mm. The wheel diameter is R15, which means it fits to a 15 inch/381mm diameter wheel. The total circumference of the tyre is mm, which is very similar to 215/80 R15
(2277.65 mm), 285/40 R22
(2471.81 mm), 225/45 R18
(2072.51 mm), 295/30 R18
(1992.4 mm), 225/55 R19
(2293.68 mm), 295/40 R21
(2417.14 mm), 225/70 R16
(2266.34 mm).