245/45 R21 - Best tyres 2026 - market overview, tests, reviews

245/45 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 - 45 is height of the tyre, which is calculated as 45% of the tyre width (245mm), which means the sidewall height has 110.25 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 225/50 R18(2143.19 mm), 295/35 R19(2164.87 mm), 225/60 R18(2284.57 mm), 305/30 R20(2170.84 mm), 235/35 R20(2112.72 mm), 235/50 R17(2094.81 mm), 235/60 R17(2242.47 mm).