Standard Envelope Sizes in India: Full Chart (mm, cm, in)

In India, the most common business envelope sizes are C4 (229 × 324 mm), C5 (162 × 229 mm), C6 (114 × 162 mm) and DL (110 × 220 mm). These follow the ISO 216 international standard, where each C-size envelope is built to hold the matching A-size sheet of paper.

This guide gives you the complete envelope size chart in millimetres, centimetres and inches, explains which envelope fits which paper, and helps you pick the right size for letters, invoices, certificates and bulk business mailing.

Standard Envelope Size Chart (mm, cm and Inches)

Envelope sizes in India follow the ISO 216 C-series, the same standard used across Europe and most of Asia. Here is the complete chart:

ISO 216 Envelope Sizes

Envelope	Millimetres	Centimetres	Inches	Holds
C3	324 × 458 mm	32.4 × 45.8 cm	12.8 × 18 in	A3 flat
C4	229 × 324 mm	22.9 × 32.4 cm	9 × 12.8 in	A4 flat
C5	162 × 229 mm	16.2 × 22.9 cm	6.4 × 9 in	A5 flat, or A4 folded once
C6	114 × 162 mm	11.4 × 16.2 cm	4.5 × 6.4 in	A6 flat, or A4 folded twice
C7	81 × 114 mm	8.1 × 11.4 cm	3.2 × 4.5 in	A7 flat, small cards
DL	110 × 220 mm	11 × 22 cm	4.3 × 8.7 in	A4 folded in three

Inch values are rounded. The exact conversion for a C4 envelope, for example, is 9.02 × 12.76 inches.

Which Envelope Fits Which Paper Size?

The ISO system makes this simple: the C-number matches the A-number. A C4 envelope holds A4, a C5 holds A5, a C6 holds A6. Each C-size is slightly larger than its A-size so the paper slides in without bending.

Paper size	Paper (mm)	Envelope, unfolded	Envelope, folded
A3	297 × 420 mm	C3	C4 (folded once)
A4	210 × 297 mm	C4	C5, C6 or DL
A5	148 × 210 mm	C5	C6 (folded once)
A6	105 × 148 mm	C6	C7

If you print business documents on A4, a C4 envelope is the size that keeps them flat and uncreased.

What Is an “A4 Envelope”?

This is the single most common source of confusion. There is no official ISO size called an A4 envelope. The A-series describes paper, not envelopes. But because a C4 envelope is the one that holds an A4 sheet unfolded, buyers, stationery shops and printers across India simply call it an A4 envelope.

So if a supplier quotes you for an “A4 envelope”, they almost always mean a C4 — 229 × 324 mm. The same product is also sold as an A4 document envelope, an A4 envelope cover or a C4 document mailer.

C4 vs C5 vs C6 vs DL: Which Should You Use?

Choosing comes down to one question: does the document need to arrive flat, or can it be folded?

• C4 — keep it flat. Contracts, tenders, certificates, mark sheets, legal papers, catalogues. Anything that would look unprofessional with a crease down the middle. See our custom C4 envelopes.
• C5 — the middle ground. Holds A5 flat or A4 folded once. Good for multi-page letters, statements and folded brochures. Our A5 envelopes cover this size.
• DL — standard business letter. The classic long envelope for invoices, letters and statements folded in three. See our Long Envelope #10.
• C6 — small and personal. Invitations, greeting cards, thank-you notes. For weddings and celebrations, shagun envelopes are the traditional Indian choice.

Cost note: smaller envelopes use less paper and often weigh less, so folding an A4 into a DL can reduce both printing and postage cost on high-volume mailings. Just make sure the document is one that can be folded.

Envelope Paper Weight: 80, 100 or 120 GSM?

GSM stands for grams per square metre — the weight of the paper. Heavier paper is more opaque and more durable, but costs more to print and post.

• 80 GSM — lightest option, lowest postage cost. Suitable for single-sheet mailings where the contents are not confidential.
• 100 GSM — the standard for Indian business use. Opaque enough that the document inside cannot be read through the paper, and strong enough for courier handling.
• 120 GSM — for bulky contents, legal documents, or when the envelope itself is part of the brand impression.

Custom Printed Envelopes in India

A printed envelope does two things a plain one cannot: it tells the recipient who the letter is from before they open it, and it makes a return address unnecessary to write by hand on every piece.

At Tagsen we print custom envelopes in every standard size on 100 GSM Alabaster paper, with your logo, business name, address, GST details or full custom artwork. Minimum order is 100 pieces, and C4 envelopes start at ₹1,900 per 100 — about ₹19 each.

Browse our full envelope printing range, or print matching company letterheads for a consistent stationery set. For orders above 500 pieces, request a bulk quote.

Frequently Asked Questions

What is the standard envelope size in India?

India follows the ISO 216 standard. The most widely used business sizes are C4 (229 × 324 mm), C5 (162 × 229 mm) and DL (110 × 220 mm).

Which envelope size fits an A4 sheet without folding?

A C4 envelope, measuring 229 × 324 mm. It is about 19 mm wider and 27 mm taller than an A4 page.

Is a C4 envelope the same as an A4 envelope?

Yes, in common usage. There is no official A4 envelope size, but because a C4 holds an A4 sheet unfolded, most buyers in India call it an A4 envelope.

What is the difference between C4 and C5 envelopes?

C4 (229 × 324 mm) holds A4 flat. C5 (162 × 229 mm) is exactly half the size and holds A4 folded once, or A5 flat.

What size is a DL envelope?

DL measures 110 × 220 mm (4.3 × 8.7 inches) and holds an A4 sheet folded in three. It is the standard size for business letters and invoices.

What GSM should a business envelope be?

100 GSM is the standard for Indian business use — opaque enough to conceal the contents and strong enough for courier handling.

Can I get envelopes printed with my company logo?

Yes. Tagsen prints custom envelopes in all standard sizes with your logo, business name, address and brand colours, starting from 100 pieces.

Written and reviewed by the Tagsen India print production team. Last updated: [DD Month YYYY].