A1, A2, A3, A4, A5, A6? Need Help?
The A standard paper size is based on each A size being half the size the previous A size. For example, A2 is half the size of A1.
Most people know the size A4. Think of a standard sheet of paper – an A4 foolscap page, a bill in the post, a letter – it’s the most common size.
Now put two A4 pages side by side in an upright portrait orientation. This is A3.
Now stack 2 more A4’s on top of these two, that’s A2.
Now put 4 sheets to the side of these 4, that’s A1 and so on till you get to A0.
The A4 range keeps doubling.
2 A4’s = A3
2 A3’s = A2
2 A2’s = A1
2 A1’s = A0
Same applies in reverse. If you halve or fold your A4 page into two, its now A5. Fold again, and it’s A6. Fold again, A7.
We’re confusing you! Enough of the words. See below for a good visual diagram to explain.