255/30 R21 - Best tyres 2025 - market overview, tests, reviews

255/30 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 - 30 is height of the tyre, which is calculated as 30% of the tyre width (255mm), which means the sidewall height has 76.5 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 235/50 R19(2254.41 mm), 235/65 R16(2236.5 mm), 155/70 R13(1719.08 mm), 245/35 R19(2054.92 mm), 165/60 R14(1739.19 mm), 245/45 R17(2049.26 mm), 170/60 R17(1997.42 mm).