215/50 R15 doesn't belong to the most popular dimensions for winter tyres - there are 0 tyre models available, which can be compared to 155/60 R15, 170/60 R17, 160/60 R14. Let's break down the sizing - 50 is height of the tyre, which is calculated as 50% of the tyre width (215mm), which means the sidewall height has 107.5 mm. The wheel diameter is R15, which means it fits to a 15 inch/381mm diameter wheel. The total circumference of the tyre is 1872.39 mm, which is very similar to 185/65 R14(1872.7 mm), 205/40 R17(1871.76 mm), 165/65 R15(1870.82 mm), 195/55 R15(1870.82 mm), 165/80 R13(1866.73 mm), 215/45 R16(1884.64 mm), 185/50 R16(1857.94 mm).