Side-by-Side Comparison
North American (ANSI & Arch)
ANSI D vs. US Half Letter
Comparing 2 standards across 8 specifications. 8 key differences identified.
Comparing:
ANSI D
US Half Letter
ANSI D is an engineering drawing paper standard defined by ANSI/ASME Y14.1, measuring 22.0 × 34.0 inches (558.8 × 863.6 mm). Formed by doubling ANSI C, it is the classic North American engineering blueprint format for civil engineering site plans, automotive chassis designs, and aerospace sub-assemblies.
US Half Letter (Statement / Memo) is a North American paper format measuring 5.5 × 8.5 inches (139.7 × 215.9 mm), created by cutting a standard US Letter sheet in half across its width. It is the dominant US format for medical prescription pads, restaurant guest checks, bank statement inserts, and mini binders.
Specification Comparison Table
8 Parameters| Parameter / Spec | ||
|---|---|---|
|
Width × Height (Imperial)
|
22.00 × 34.00 in | 5.50 × 8.50 in |
|
Width × Height (Metric)
|
558.8 × 863.6 mm | 139.7 × 215.9 mm |
|
Aspect Ratio
|
1 : 1.5455 (11 : 17 — identical to ANSI B) | 1 : 1.5455 (11 : 17) |
|
International ISO Equivalent
|
A1 (594 × 841 mm) | A5 (148 × 210 mm — slightly wider and shorter) |
|
Primary Applications
|
Civil engineering utility plans, automotive chassis CAD plots, aerospace mechanical schematics | Medical clinic prescription pads, restaurant receipt slips, flight pilot kneeboard checklists |
|
ANSI Hierarchy
|
ANSI D = 2 × ANSI C = 4 × ANSI B = 8 × ANSI A | — |
|
Derivation
|
— | Exactly half of a US Letter sheet (8.5 × 11 in cut across the 11 in dimension) |
|
Matching Binder Standard
|
— | Mini 3-ring binder (2.75 in ring spacing) |