Envelope Sizes (DL, C4, C5, C6) in mm and Inches for PDF Templates
Envelope templates are easy to get subtly wrong: a window in the wrong place, a flap that is 2 mm off. Know the standard sizes and check yours against them.
Standard sizes
| Name | mm | inches | Fits |
|---|---|---|---|
| C6 | 114 x 162 | 4.49 x 6.38 | A6, or A5 folded once |
| DL | 110 x 220 | 4.33 x 8.66 | A4 folded in three |
| C65 | 114 x 229 | 4.49 x 9.02 | A4 folded in three (alt.) |
| C5 | 162 x 229 | 6.38 x 9.02 | A5 flat, A4 folded once |
| C4 | 229 x 324 | 9.02 x 12.76 | A4 flat |
Check a template
- Open the template PDF in PdfRuler, in mm.
- Read the page size or, for a flat die-line, auto-measure the main panel.
- Compare with the table. A DL panel should be 110 x 220 mm.
Check the address window
Window position is set by the envelope maker, so check it against their template. Place a point on the envelope's bottom-left corner and another on the window's corner, or drag guides to the window edges and read their distances from the corner. Pick the bottom-left origin so the numbers match how printers specify it.
Also check the fold
An A4 letter folded in thirds has panels of 99 mm each. If your letter template has fold marks, measure the gaps between them.
Frequently asked questions
What size is a DL envelope?
DL is 110 x 220 mm (4.33 x 8.66 in) and holds an A4 sheet folded in three.
What size is a C5 envelope?
C5 is 162 x 229 mm (6.38 x 9.02 in); it holds A5 flat or A4 folded once.
How do I check an envelope PDF template?
Open it in PdfRuler, auto-measure the panels and compare them with the standard sizes.
