Paper Sizes Explained
Complete guide to understanding paper sizes: US formats, ISO standards, and choosing the right size for your graph paper
Overview of Paper Size Standards
Paper sizes vary around the world, with two main systems in use:
- US/Imperial System: Used primarily in the United States, Canada, and the Philippines
- ISO Standard (International): Used in most countries worldwide, based on metric measurements
Quick Comparison: The most common sizes are US Letter (8.5" × 11") and ISO A4 (210 × 297mm or 8.27" × 11.69"). A4 is slightly narrower and taller than Letter.
US/Imperial Paper Sizes
The United States uses a system of paper sizes based on inches, with no consistent mathematical relationship between sizes.
Common US Paper Sizes
Letter (8.5" × 11")
- Dimensions: 8.5 inches × 11 inches (215.9mm × 279.4mm)
- Most common use: Standard for business documents, school papers, printing
- Graph paper use: General purpose, math homework, office work
- Availability: Widely available, default printer size in the US
Legal (8.5" × 14")
- Dimensions: 8.5 inches × 14 inches (215.9mm × 355.6mm)
- Most common use: Legal documents, contracts, forms
- Graph paper use: Extended vertical space for long graphs or lists
- Availability: Common in offices, may require special printer tray
Tabloid/Ledger (11" × 17")
- Dimensions: 11 inches × 17 inches (279.4mm × 431.8mm)
- Orientation: Tabloid is portrait, Ledger is landscape (same size)
- Most common use: Large drawings, presentations, newspapers
- Graph paper use: Engineering drawings, architectural plans, large-scale work
- Availability: Requires large-format printer or plotter
Half Letter (5.5" × 8.5")
- Dimensions: 5.5 inches × 8.5 inches (139.7mm × 215.9mm)
- Most common use: Pocket notebooks, planners, small booklets
- Graph paper use: Portable notebooks, bullet journals, sketching
- Availability: Cut from Letter size or specialty paper
Junior Legal (8" × 5")
- Dimensions: 8 inches × 5 inches (203.2mm × 127mm)
- Most common use: Small legal pads, note cards
- Graph paper use: Quick notes, small sketches
- Availability: Less common, specialty paper stores
ISO Paper Sizes (International Standard)
The ISO 216 standard defines paper sizes used in most of the world. The system is based on a consistent aspect ratio of √2:1 (approximately 1.414:1), which has the unique property that when you cut or fold the paper in half, the resulting pieces maintain the same aspect ratio.
The √2 Advantage: The ISO system's aspect ratio means that scaling between sizes is seamless. An A4 page folded in half becomes A5, and two A4 sheets side-by-side equal A3. This mathematical elegance makes the system highly practical.
ISO A Series (Most Common)
The A series is the most widely used and is based on A0, which has an area of 1 square meter.
A0 (841 × 1189mm)
- Dimensions: 841mm × 1189mm (33.1" × 46.8")
- Most common use: Technical drawings, posters, large-format artwork
- Graph paper use: Engineering plans, architectural drawings
- Availability: Specialty paper, plotting services
A1 (594 × 841mm)
- Dimensions: 594mm × 841mm (23.4" × 33.1")
- Most common use: Technical drawings, flip charts
- Graph paper use: Large-scale technical work
- Availability: Office supply stores, plotting services
A2 (420 × 594mm)
- Dimensions: 420mm × 594mm (16.5" × 23.4")
- Most common use: Drawings, diagrams, large-format documents
- Graph paper use: Detailed drawings, presentations
- Availability: Art supply stores, specialty printers
A3 (297 × 420mm)
- Dimensions: 297mm × 420mm (11.7" × 16.5")
- Most common use: Newspapers, diagrams, small posters
- Graph paper use: Large graphs, engineering work
- Availability: Common, many printers support A3
A4 (210 × 297mm) ⭐ Most Common
- Dimensions: 210mm × 297mm (8.27" × 11.69")
- Most common use: Standard international paper size for documents
- Graph paper use: General purpose, education, office work
- Availability: Universal standard, default printer size worldwide (except US)
A5 (148 × 210mm)
- Dimensions: 148mm × 210mm (5.83" × 8.27")
- Most common use: Notebooks, booklets, half-page documents
- Graph paper use: Portable notebooks, bullet journals
- Availability: Common in notebooks and stationery
A6 (105 × 148mm)
- Dimensions: 105mm × 148mm (4.13" × 5.83")
- Most common use: Postcards, small notebooks, pocket journals
- Graph paper use: Pocket sketching, small planning pages
- Availability: Specialty stationery
ISO B Series
The B series is a geometric mean between consecutive A sizes, used when A sizes don't quite fit the need.
Common B Sizes
- B4 (250 × 353mm): Between A4 and A3, used for books and pamphlets
- B5 (176 × 250mm): Between A5 and A4, popular for books and notebooks
- B6 (125 × 176mm): Small books and pamphlets
ISO C Series (Envelopes)
The C series is designed for envelopes. A C-size envelope fits an A-size sheet unfolded.
Common C Sizes
- C4 (229 × 324mm): Holds A4 unfolded
- C5 (162 × 229mm): Holds A5 unfolded or A4 folded once
- C6 (114 × 162mm): Holds A6 unfolded or A5 folded once
A4 vs Letter: Key Differences
Since these are the two most common paper sizes worldwide, understanding their differences is important:
Dimension Comparison
- Letter: 8.5" × 11" (215.9mm × 279.4mm) - 93.5 sq in
- A4: 210mm × 297mm (8.27" × 11.69") - 88.3 sq in
Key Differences
- Width: Letter is wider (8.5" vs 8.27")
- Height: A4 is taller (11.69" vs 11")
- Area: Letter is slightly larger (about 6% more area)
- Aspect ratio: Letter is 1.294:1, A4 is 1.414:1 (√2)
Practical Implications
- Printing: Documents designed for one size may not print correctly on the other
- Margins: May need adjustment when switching between sizes
- File sharing: International documents often default to A4
- Availability: Letter in North America, A4 everywhere else
Choosing the Right Paper Size for Graph Paper
- Elementary school: Letter/A4 for most work
- High school/College: Letter/A4 standard, Legal for extended graphs
- Graphing practice: Larger sizes (A3/Tabloid) for better visibility
For Engineering and Technical Work
- Detailed drawings: A3, A2, or Tabloid minimum
- Standard documentation: Letter/A4
- Large projects: A1, A0, or custom sizes
For Personal Organization
- Desk planners: Letter/A4
- Portable notebooks: Half Letter, A5, or A6
- Bullet journals: A5 is most popular
- Sketching: A4/Letter for practice, larger for finished work
- Pattern design: Size depends on pattern repeat
- Cross-stitch: Larger sizes for easier counting
Paper Size Selection Tips
Consider Your Location
- United States/Canada: Use Letter size for maximum compatibility
- International: A4 is the universal standard
- Mixed environments: Choose based on your primary collaborators
Consider Your Printer
- Check maximum paper size capability
- Verify tray configuration for non-standard sizes
- Consider manual feed for specialty sizes
- Check borderless printing capabilities if needed
Consider Your Project
- Portability: Smaller sizes for mobile use
- Detail level: Larger sizes for complex work
- Collaboration: Match team's standard size
- Archive/binding: Consider filing system requirements
Custom Paper Sizes
Our graph paper generator allows you to create graph paper in any custom size:
- Enter exact dimensions in inches or millimeters
- Create specialty sizes for unique projects
- Match specific printer or plotter requirements
- Design for custom binding or framing
Quick Reference Table
US Sizes
- Letter: 8.5" × 11" (215.9 × 279.4mm)
- Legal: 8.5" × 14" (215.9 × 355.6mm)
- Tabloid: 11" × 17" (279.4 × 431.8mm)
- Half Letter: 5.5" × 8.5" (139.7 × 215.9mm)
ISO A Series
- A4: 210 × 297mm (8.27" × 11.69")
- A3: 297 × 420mm (11.7" × 16.5")
- A5: 148 × 210mm (5.83" × 8.27")
- A6: 105 × 148mm (4.13" × 5.83")
Pro Tip: When creating graph paper, always match your paper size selection to the actual paper loaded in your printer to avoid scaling issues and ensure accurate grid dimensions.
Generate your custom graph paper now with the exact paper size you need!