225/40 R16 doesn't belong to the most popular dimensions for winter 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 - 40 is height of the tyre, which is calculated as 40% of the tyre width (225mm), which means the sidewall height has 90 mm. The wheel diameter is R16, which means it fits to a 16 inch/406.4mm diameter wheel. The total circumference of the tyre is mm, which is very similar to 215/75 R15
(2210.11 mm), 285/40 R19
(2232.42 mm), 225/40 R19
(2081.62 mm), 285/65 R17
(2520.5 mm), 225/55 R17
(2134.08 mm), 295/35 R21
(2324.46 mm), 225/65 R17
(2275.46 mm).
