245/45 R21 - Best allround tyres 2025 - market overview, tests, reviews

245/45 R21 doesn't belong to the most popular dimensions for allround tyres - there are 0 tyre models available, which can be compared to 155/60 R15, 170/60 R17, 160/60 R14. 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 2368.45 mm, which is very similar to 275/40 R21(2366.88 mm), 245/50 R20(2365.62 mm), 275/45 R20(2373.47 mm), 265/70 R15(2362.48 mm), 245/60 R18(2359.96 mm), 245/65 R17(2357.14 mm), 285/35 R22(2382.27 mm). There are multiple speed indexes available for allround tyres in 245/45 R21: W(270km/h). The same goes for weight indexes: 104.