Side-by-Side Comparison
North American (ANSI & Arch)
ANSI C vs. US Half Letter
Comparing 2 standards across 8 specifications. 8 key differences identified.
Comparing:
ANSI C
US Half Letter
ANSI C is an engineering paper standard defined by ANSI/ASME Y14.1, measuring 17.0 × 22.0 inches (431.8 × 558.8 mm). Formed by joining two ANSI B (Tabloid) sheets or four ANSI A (Letter) sheets, it is the entry format for mechanical CAD assembly drawings and electrical wiring schematics.
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)
|
17.00 × 22.00 in | 5.50 × 8.50 in |
|
Width × Height (Metric)
|
431.8 × 558.8 mm | 139.7 × 215.9 mm |
|
Aspect Ratio
|
1 : 1.2941 (17 : 22 — identical aspect ratio to ANSI A) | 1 : 1.5455 (11 : 17) |
|
International ISO Equivalent
|
A2 (420 × 594 mm) | A5 (148 × 210 mm — slightly wider and shorter) |
|
Primary Applications
|
Mechanical component CAD drawings, electrical control panel schematics, industrial plumbing diagrams | Medical clinic prescription pads, restaurant receipt slips, flight pilot kneeboard checklists |
|
ANSI Hierarchy
|
ANSI C = 2 × ANSI B (Tabloid) = 4 × ANSI A (Letter) | — |
|
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) |