Envelope reference · historical ISO designation
DL envelope size
A long, narrow business envelope designed around an A4 sheet folded into thirds, widely used for invoices, statements, and office correspondence.
Download layout templatesDirect answer
DL dimensions and paper fit
In landscape orientation, DL measures 110 × 220 mm, or 4.33 × 8.66 inches. A4 folded into thirds to roughly 99 × 210 mm.
| Unit | Width | Height |
|---|---|---|
| Millimeters | 110 mm | 220 mm |
| Centimeters | 11 cm | 22 cm |
| Inches | 4.33 in | 8.66 in |
| Pixels at 300 DPI | 1299 px | 2598 px |
Insert & folding
What fits inside DL?
A4 folded into thirds to roughly 99 × 210 mm. Use a letter fold or Z-fold with two folds parallel to the short edge of A4.
Comparison
How DL differs from nearby envelopes
DL is 58 mm longer and 4 mm narrower than C6. It is close to—but not identical with—a US No. 10 envelope at 4⅛ × 9½ inches.
Works well for
Common DL uses
- Invoices
- Business letters
- Statements
- Window-envelope mail
Check before using
Where it can go wrong
- US No. 10 artwork at 100% scale
- A4 folded in half
- Window placement based only on page dimensions
Postal note
Dimensions do not determine postage by themselves.
Window position, machine-read zones, thickness, and postage rules vary. Use the envelope supplier’s dieline for production artwork.
Historical measurement source
Based on historical ISO envelope designations.
The official ISO page identifies ISO 269:1985 as withdrawn. Paper Size Lab cites it as the historical designation source, not as a current postal requirement.
View ISO 269:1985 statusQuestions people ask
DL envelope FAQ
What size is a DL envelope?
DL measures 110 × 220 mm, or 4.33 × 8.66 inches.
What paper fits in a DL envelope?
A4 folded into thirds to roughly 99 × 210 mm.
How should paper be folded for a DL envelope?
Use a letter fold or Z-fold with two folds parallel to the short edge of A4.
Does a DL envelope qualify for standard postage?
Window position, machine-read zones, thickness, and postage rules vary. Use the envelope supplier’s dieline for production artwork.