🔗 A0 = 1

I recently watched a YouTube video by Hannah Fry, about the An paper sizes.

I knew about the successive doubling (e.g. 2 x A4 = A3, 2 x A3 = A2, 2 x A2 = A1, 2 x A1 = A0).

What I did not know was that A0 is exactly 1 m² in size, according to the ISO 216 standard.

So, that means that A4 is four halvings of 1 m² or 1/16 m². Who knew?