C8 Envelope Size
C8 measures 57 × 81 mm (2.24 × 3.19 in). It is the smallest standard ISO C envelope, sized for an A8 card, sitting between A8 and B8.
C8 measures 57 millimetres wide and 81 millimetres tall.
C8 Dimensions in Each Unit
C8 is 57 × 81 mm, which is 5.7 × 8.1 cm or 2.24 × 3.19 in. It is C7 cut in half.
| Unit | Width | Height | Width × height | Copy |
|---|---|---|---|---|
| Millimetres (mm) | 57 | 81 | 57 × 81 mm | |
| Centimetres (cm) | 5.7 | 8.1 | 5.7 × 8.1 cm | |
| Metres (m) | 0.057 | 0.081 | 0.057 × 0.081 m | |
| Inches (in) | 2.24 | 3.19 | 2.24 × 3.19 in | |
| Feet (ft) | 0.19 | 0.27 | 0.19 × 0.27 ft | |
| Points (pt) | 162 | 230 | 162 × 230 pt | |
| Picas (pc) | 13.5 | 19.1 | 13.5 × 19.1 pc | |
| Pixels at 72 DPI | 162 | 230 | 162 × 230 px | |
| Pixels at 150 DPI | 337 | 478 | 337 × 478 px | |
| Pixels at 300 DPI | 673 | 957 | 673 × 957 px | |
| Pixels at 600 DPI | 1346 | 1913 | 1346 × 1913 px |
Pixel counts follow from the resolution: pixels = millimetres ÷ 25.4 × DPI. More on the DPI and pixels page.
C8 Shape and Area
| Aspect ratio | 1 : 1.421 (√2) |
|---|---|
| Area | 0.00462 m² · 4,617 mm² |
| Diagonal | 99 mm · 3.9 in |
| ISO 216 tolerance | ± 1.5 mm each side |
| Governing standard | ISO 216:2007 |
C8 to Scale
C8 is half of C7, the smallest in the Envelope Sizes. Put C8 next to another size in the comparison tool.
Frequently Asked Questions
What size is a C8 envelope?
C8 is 57 by 81 mm, or 2.24 by 3.19 inches, the smallest standard ISO C envelope.
What fits in a C8 envelope?
An A8 card flat, plus small items like coins, stamps, seeds or jewellery on a tag.
Which is bigger, C7 or C8?
C7 is the bigger of the two, at 81 × 114 mm against 57 × 81 mm for C8. It has twice the area, so two C8 envelopes cover one C7.
Envelope Sizes
✓ Dimensions per ISO 216:2007; unit values derived by formula. Reviewed . Editorial Process →