245/45 R21 - Best tyres 2025 - 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 195/60 R14(1852.28 mm), 265/35 R21(2258.49 mm), 195/70 R16(2134.4 mm), 265/45 R21(2425 mm), 205/45 R17(1936.16 mm), 265/70 R16(2442.27 mm), 205/60 R15(1969.78 mm).