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 185/50 R16
(1857.94 mm), 255/45 R18
(2157.33 mm), 185/65 R15
(1952.5 mm), 255/60 R17
(2317.87 mm), 195/45 R15
(1748.3 mm), 265/30 R20
(2095.44 mm), 195/60 R15
(1932.08 mm).
