---
title: "Envelope sizes — every size in mm and inches"
description: "Every envelope size size with dimensions in millimetres, centimetres and inches, and the standard that defines each."
url: https://atoneplace.net/size/envelope/
site: "At One Place"
---

# Envelope sizes

3 envelope sizes, with what each one actually specifies.

| Name | Millimetres | Inches | Notes |
| --- | --- | --- | --- |
| DL envelope | 220 × 110 mm | 8.66 × 4.33 | 220 × 110 mm — fits A4 folded into three. |
| C4 envelope | 229 × 324 mm | 9.02 × 12.76 | 229 × 324 mm — holds A4 unfolded. |
| C5 envelope | 162 × 229 mm | 6.38 × 9.02 | 162 × 229 mm — holds A4 folded once, or A5 flat. |

- [DL envelope size](https://atoneplace.net/size/dl-envelope/) — 220 × 110 mm — fits A4 folded into three.
- [C4 envelope size](https://atoneplace.net/size/c4-envelope/) — 229 × 324 mm — holds A4 unfolded.
- [C5 envelope size](https://atoneplace.net/size/c5-envelope/) — 162 × 229 mm — holds A4 folded once, or A5 flat.