Comparisons
Paper size comparisons
Side-by-side guides for the size decisions that actually come up: each one has a to-scale diagram, the exact measurements in every unit, and the practical rules — scaling percentages, fold maths, which to pick when. Within the ISO family the answers are elegant (everything is a doubling); across the Atlantic they are not, which is why the A4 vs Letter guide is the longest.
A4 vs US Letter
The cross-Atlantic mismatch: 6 mm of width against 18 mm of height, the asymmetric 94 % / 97 % scaling rules, and the universal layout box that prints on both.
Read the comparison →
A4 vs A5
One fold apart: A5 is exactly half an A4, which is why two A5 flyers print perfectly on one A4 sheet — same 1:√2 shape, half the area.
Read the comparison →
A3 vs A4
The doubling upward: A3 is two A4 sheets side by side — the basis of every A4 booklet and the poster size most office printers can almost reach.
Read the comparison →
A5 vs A6
The small formats: A6 is half an A5 (postcard vs flyer), and four A6 cards tile one A4 sheet with two clean cuts.
Read the comparison →