325/30 R21 - Best tyres 2025 - market overview, tests, reviews

325/30 R21 doesn't belong to the most popular dimensions for tyres - there are tyre models available, which can be compared to 325/25 R20, 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 (325mm), which means the sidewall height has 97.5 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 215/40 R17(1896.89 mm), 275/45 R20(2373.47 mm), 215/55 R17(2099.53 mm), 285/25 R20(2043.61 mm), 215/70 R16(2222.36 mm), 285/35 R22(2382.27 mm), 225/40 R18(2001.82 mm).