305/25 R21 - Best tyres 2025 - market overview, tests, reviews

305/25 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 - 25 is height of the tyre, which is calculated as 25% of the tyre width (305mm), which means the sidewall height has 76.25 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 185/50 R16(1857.94 mm), 255/45 R17(2077.54 mm), 185/65 R15(1952.5 mm), 255/55 R20(2477.15 mm), 195/45 R15(1748.3 mm), 265/30 R19(2015.65 mm), 195/60 R15(1932.08 mm).