Publishing trade size
Compare DemyDemy Book Size
A Demy book measures 138 × 216 mm (5.43 × 8.5 in). It is a UK Demy octavo trim, the step down from Royal, used for memoir, shorter non-fiction and small-format gift hardbacks.
inisDimensions
Demy measures 138 millimetres wide and 216 millimetres tall.
Demy Dimensions in Each Unit
Demy is 138 × 216 mm, which is 13.8 × 21.6 cm or 5.43 × 8.5 in.
| Unit | Width | Height | Width × height | Copy |
|---|---|---|---|---|
| Millimetres (mm) | 138 | 216 | 138 × 216 mm | |
| Centimetres (cm) | 13.8 | 21.6 | 13.8 × 21.6 cm | |
| Metres (m) | 0.138 | 0.216 | 0.138 × 0.216 m | |
| Inches (in) | 5.43 | 8.5 | 5.43 × 8.5 in | |
| Feet (ft) | 0.45 | 0.71 | 0.45 × 0.71 ft | |
| Points (pt) | 391 | 612 | 391 × 612 pt | |
| Picas (pc) | 32.6 | 51 | 32.6 × 51 pc | |
| Pixels at 72 DPI | 391 | 612 | 391 × 612 px | |
| Pixels at 150 DPI | 815 | 1276 | 815 × 1276 px | |
| Pixels at 300 DPI | 1630 | 2551 | 1630 × 2551 px | |
| Pixels at 600 DPI | 3260 | 5102 | 3260 × 5102 px |
Pixel counts follow from the resolution: pixels = millimetres ÷ 25.4 × DPI. More on the DPI and pixels page.
Demy Shape and Area
| Aspect ratio | 1 : 1.565 |
|---|---|
| Area | 0.0298 m² · 29,808 mm² |
| Diagonal | 256.3 mm · 10.09 in |
| Closest ISO size | UK, memoir and shorter non-fiction |
| Governing standard | Book trade convention (UK and US) |
Demy to Scale
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Frequently Asked Questions
What size is a Demy book?
Demy octavo is 138 by 216 mm, or about 5.43 by 8.5 inches.
What is the difference between Demy and Royal?
Both are UK octavo trims. Demy is 138 by 216 mm and Royal is 156 by 234 mm, so Royal is the larger, more substantial hardback.
Book Sizes
✓ Dimensions per Publishing trade size; unit values derived by formula. Reviewed . Editorial Process →