# item.guide
Side-by-Side Comparison A-Series (ISO 216)

A1 vs. A3

Comparing 2 standards across 7 specifications. 6 key differences identified.

Comparing:
A1 A1
A3 A3

A1 is an ISO 216 standard paper size measuring 594 × 841 mm (23.4 × 33.1 inches), with an exact surface area of 0.500 square meters (half of A0). It is the premier standard format for architectural blueprints, structural engineering drawings, municipal planning maps, and large-format flipcharts.

View full A1 spec sheet →

A3 is an ISO 216 standard paper size measuring 297 × 420 mm (11.7 × 16.5 inches), with a surface area of 0.125 square meters (one eighth of A0). It is the standard large-format paper supported by commercial office multifunction printers (MFPs), widely used for financial spreadsheets, two-page A4 magazine spreads, and engineering diagrams.

View full A3 spec sheet →

Specification Comparison Table

7 Parameters
Parameter / Spec
A1 A1
A3 A3
Width × Height (Metric)
594 × 841 mm 297 × 420 mm
Width × Height (Imperial)
23.4 × 33.1 in 11.7 × 16.5 in
Nominal Surface Area
0.500 m² (500,000 mm²) 0.125 m² (125,000 mm²)
Exact Aspect Ratio
1 : √2 (1 : 1.4142) 1 : √2 (1 : 1.4142)
Weight of Standard 80 gsm Sheet
40.0 grams 10.0 grams
Halving Relationship
Cut in half yields 2 sheets of A2 Cut or folded in half yields 2 sheets / 4 pages of A4
Primary Applications
Architectural blueprints, conference presentation boards, large flipcharts, theatrical event posters Office spreadsheets, folded A4 booklets, ledger accounting, small posters