255/50 R21 - Best tyres 2025 - market overview, tests, reviews

255/50 R21 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 - 50 is height of the tyre, which is calculated as 50% of the tyre width (255mm), which means the sidewall height has 127.5 mm. The wheel diameter is R21, which means it fits to a 21 inch/533.4mm diameter wheel. The total circumference of the tyre is mm, which is very similar to 205/50 R17(2000.57 mm), 275/30 R19(2034.5 mm), 205/65 R16(2113.98 mm), 275/40 R19(2207.28 mm), 215/45 R16(1884.64 mm), 275/50 R20(2459.87 mm), 215/60 R16(2087.27 mm).