Side-by-Side Comparison
North American (ANSI & Arch)
ANSI C vs. US Letter
Comparing 2 standards across 10 specifications. 10 key differences identified.
Comparing:
ANSI C
US 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 Letter (ANSI A) is the standard business and consumer paper size in the United States, Canada, and parts of Mexico, measuring exactly 8.5 × 11.0 inches (215.9 × 279.4 mm). Standardized under ANSI/ASME Y14.1, it is slightly wider and shorter than the international ISO 216 A4 format.
Specification Comparison Table
10 Parameters| Parameter / Spec | ||
|---|---|---|
|
Width × Height (Imperial)
|
17.00 × 22.00 in | 8.50 × 11.00 in |
|
Width × Height (Metric)
|
431.8 × 558.8 mm | 215.9 × 279.4 mm |
|
Aspect Ratio
|
1 : 1.2941 (17 : 22 — identical aspect ratio to ANSI A) | 1 : 1.2941 (17 : 22 — not √2) |
|
ANSI Hierarchy
|
ANSI C = 2 × ANSI B (Tabloid) = 4 × ANSI A (Letter) | — |
|
International ISO Equivalent
|
A2 (420 × 594 mm) | — |
|
Primary Applications
|
Mechanical component CAD drawings, electrical control panel schematics, industrial plumbing diagrams | — |
|
ANSI Series Designation
|
— | ANSI A (Base engineering format) |
|
Comparison to ISO A4
|
— | US Letter is 5.9 mm wider and 17.6 mm shorter than A4 (210 × 297 mm) |
|
Standard Office Weight
|
— | 20 lb Bond (approx. 75 gsm) or 24 lb Bond (approx. 90 gsm) |
|
Matching Envelope Standard
|
— | US #10 Envelope (4.125 × 9.50 in / 104.8 × 241.3 mm) |