About paper sizes

Paper Sizes

Paper sizes are standardized by various organizations around the world. The two most commonly used standards are the International Organization for Standardization (ISO) and the North American standard.

1. ISO Paper Sizes

The ISO 216 standard is used worldwide and includes the A, B, and C series of paper sizes.

• A Series: The A series is the most commonly used paper size for everyday printing and includes sizes such as A0, A1, A2, A3, A4, A5, A6, A7, A8, A9, and A10. The sizes are based on a ratio of 1:√2, with A0 being the largest and A10 the smallest.
  • A0: 841 x 1189 mm (33.1 x 46.8 in)
  • A1: 594 x 841 mm (23.4 x 33.1 in)
  • A2: 420 x 594 mm (16.5 x 23.4 in)
  • A3: 297 x 420 mm (11.7 x 16.5 in)
  • A4: 210 x 297 mm (8.3 x 11.7 in) – commonly used for letters and documents.
  • A5: 148 x 210 mm (5.8 x 8.3 in) – commonly used for booklets.
  • A6: 105 x 148 mm (4.1 x 5.8 in)
  • A7: 74 x 105 mm (2.9 x 4.1 in)
  • A8: 52 x 74 mm (2.0 x 2.9 in)
  • A9: 37 x 52 mm (1.5 x 2.0 in)
  • A10: 26 x 37 mm (1.0 x 1.5 in)
• B Series: The B series is used for larger formats and offers a wider range of sizes.
  • B0: 1000 x 1414 mm (39.4 x 55.7 in)
  • B1: 707 x 1000 mm (27.8 x 39.4 in)
  • B2: 500 x 707 mm (19.7 x 27.8 in)
  • B3: 353 x 500 mm (13.9 x 19.7 in)
  • B4: 250 x 353 mm (9.8 x 13.9 in)
  • B5: 176 x 250 mm (6.9 x 9.8 in)
  • B6: 125 x 176 mm (4.9 x 6.9 in)
  • B7: 88 x 125 mm (3.5 x 4.9 in)
  • B8: 62 x 88 mm (2.4 x 3.5 in)
  • B9: 44 x 62 mm (1.7 x 2.4 in)
  • B10: 31 x 44 mm (1.2 x 1.7 in)
• C Series: The C series is primarily used for envelopes to fit A series paper.
  • C0: 917 x 1297 mm (36.1 x 51.1 in)
  • C1: 648 x 917 mm (25.5 x 36.1 in)
  • C2: 458 x 648 mm (18.0 x 25.5 in)
  • C3: 324 x 458 mm (12.8 x 18.0 in)
  • C4: 229 x 324 mm (9.0 x 12.8 in)
  • C5: 162 x 229 mm (6.4 x 9.0 in) – fits A4 paper folded in half.
  • C6: 114 x 162 mm (4.5 x 6.4 in) – fits A4 paper folded twice or A5 folded once.
  • C7: 81 x 114 mm (3.2 x 4.5 in)
  • C8: 57 x 81 mm (2.2 x 3.2 in)
  • C9: 40 x 57 mm (1.6 x 2.2 in)
  • C10: 28 x 40 mm (1.1 x 1.6 in)

2. North American Paper Sizes

The North American system is based on traditional sizes, commonly used in the United States and Canada.

• Letter: 8.5 x 11 inches – the standard for office and school use.
• Legal: 8.5 x 14 inches – used for legal documents.
• Tabloid: 11 x 17 inches – often used for newspapers.
• Ledger: 17 x 11 inches – used for accounting ledgers.

Envelope Sizes

Choosing the right envelope size is crucial to ensure that your documents fit perfectly and are presented professionally.

1. ISO Envelope Sizes

The C series of envelopes is designed to fit A series paper sizes.

• C4: 229 x 324 mm (9.0 x 12.8 in) – fits A4 paper without folding.
• C5: 162 x 229 mm (6.4 x 9.0 in) – fits A4 paper folded in half.
• C6: 114 x 162 mm (4.5 x 6.4 in) – fits A4 paper folded twice or A5 folded once.
• C7: 81 x 114 mm (3.2 x 4.5 in) – fits A5 paper folded twice or A6 folded once.
• DL: 110 x 220 mm (4.3 x 8.7 in) – fits A4 paper folded twice (commonly used for business letters).

2. North American Envelope Sizes

Envelopes in North America follow a different naming and sizing convention.

• #10 Envelope: 4.125 x 9.5 inches – standard business envelope size.
• #9 Envelope: 3.875 x 8.875 inches – often used for reply envelopes.
• A2 Envelope: 4.375 x 5.75 inches – commonly used for invitations and greeting cards.
• A6 Envelope: 4.75 x 6.5 inches – also used for invitations and greeting cards.
• A7 Envelope: 5.25 x 7.25 inches – fits 5 x 7 inch cards, popular for invitations.
• Catalog Envelope: Various sizes such as 6 x 9 inches, 9 x 12 inches – used for larger documents without folding.

Choosing the Right Size

Selecting the correct paper and envelope size depends on your specific needs. For standard office documents, A4 or Letter size is typically used. If you’re sending out invitations or greeting cards, A2, A6, or A7 envelopes paired with corresponding paper sizes work best. For larger documents or presentations, consider using B series paper for a professional look.

Understanding these sizes and their appropriate uses ensures your documents and mailings look professional and meet the expected standards. Whether for personal, business, or creative projects, knowing the right paper and envelope sizes can make a significant difference in presentation and functionality.