245/35 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 - 35 is height of the tyre, which is calculated as 35% of the tyre width (245mm), which means the sidewall height has 85.75 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 205/65 R16
(2113.98 mm), 275/40 R20
(2287.08 mm), 215/45 R16
(1884.64 mm), 275/55 R17
(2306.87 mm), 215/60 R16
(2087.27 mm), 285/30 R21
(2212.94 mm), 215/75 R16
(2289.91 mm).
