Mail envelope sizes

Here are the standard sizes for mail envelopes in the United States:

Letter Envelopes

• 10 Envelope: 4 1/8" x 9 1/2" (10.5 cm x 24.1 cm)

• 11 Envelope: 4 1/2" x 10 3/8" (11.4 cm x 26.4 cm)

Large Envelopes

• Large Flat Envelope: 6 1/8" x 11 1/2" (15.6 cm x 29.2 cm)
• Large Envelope: 6 1/2" x 12 3/4" (16.5 cm x 32.4 cm)

Specialty Envelopes

• Catalog Envelope: 6 1/2" x 12 3/4" (16.5 cm x 32.4 cm)
• Booklet Envelope: 6 1/2" x 9 1/2" (16.5 cm x 24.1 cm)
• Long Envelope: 9 1/2" x 4 1/2" (24.1 cm x 11.4 cm)

International Envelopes

• International Letter Envelope: 6 1/2" x 11 1/2" (16.5 cm x 29.2 cm)
• International Large Envelope: 9 1/2" x 12 3/4" (24.1 cm x 32.4 cm)

Other Envelope Sizes

• A2 Envelope: 4 3/8" x 5 3/4" (11.1 cm x 14.6 cm)
• A6 Envelope: 3 5/8" x 5 1/2" (9.2 cm x 14 cm)
• C6 Envelope: 3 3/4" x 6 1/2" (9.5 cm x 16.5 cm)

Please note that these sizes are standard in the United States and may vary in other countries. Additionally, some mail services may have specific requirements for envelope sizes and shapes.