A9 size

37 × 52 mm · 1.46 × 2.05 in · 104.9 × 147.4 pt

Where it comes from

Half of A8: the A8 sheet's long side (74 mm) halves and rounds down to 37 mm — ISO 216's halve-and-floor rule.

Derived from the ISO 216 construction — no lookup required, only arithmetic.

Pixels at print resolutions

DPIPixels (portrait)Typical use
72105 × 147legacy screens
96140 × 197CSS reference
150219 × 307everyday print
300437 × 614quality print
600874 × 1228fine art / line work

The family

  • Fold A8 in half and you're holding A9.
  • Fold A9 in half and you get A10 — two of those side by side rebuild this sheet.
  • Area: 0.0019 — an 80 gsm sheet weighs 0.15 g.