Royal Book Size
A Royal book measures 156 × 234 mm (6.14 × 9.21 in). It is a UK Royal octavo trim, the standard size for hardback non-fiction and literary hardbacks, close to the US 6 by 9 inch trade size.
Royal measures 156 millimetres wide and 234 millimetres tall.
Royal Dimensions in Each Unit
Royal is 156 × 234 mm, which is 15.6 × 23.4 cm or 6.14 × 9.21 in.
| Unit | Width | Height | Width × height | Copy |
|---|---|---|---|---|
| Millimetres (mm) | 156 | 234 | 156 × 234 mm | |
| Centimetres (cm) | 15.6 | 23.4 | 15.6 × 23.4 cm | |
| Metres (m) | 0.156 | 0.234 | 0.156 × 0.234 m | |
| Inches (in) | 6.14 | 9.21 | 6.14 × 9.21 in | |
| Feet (ft) | 0.51 | 0.77 | 0.51 × 0.77 ft | |
| Points (pt) | 442 | 663 | 442 × 663 pt | |
| Picas (pc) | 36.9 | 55.3 | 36.9 × 55.3 pc | |
| Pixels at 72 DPI | 442 | 663 | 442 × 663 px | |
| Pixels at 150 DPI | 921 | 1382 | 921 × 1382 px | |
| Pixels at 300 DPI | 1843 | 2764 | 1843 × 2764 px | |
| Pixels at 600 DPI | 3685 | 5528 | 3685 × 5528 px |
Pixel counts follow from the resolution: pixels = millimetres ÷ 25.4 × DPI. More on the DPI and pixels page.
Royal Shape and Area
| Aspect ratio | 1 : 1.500 |
|---|---|
| Area | 0.0365 m² · 36,504 mm² |
| Diagonal | 281.2 mm · 11.07 in |
| Closest ISO size | UK, hardback non-fiction |
| Governing standard | Book trade convention (UK and US) |
Royal to Scale
Put Royal next to another size in the comparison tool.
Frequently Asked Questions
What size is a Royal book?
Royal octavo is 156 by 234 mm, or about 6.14 by 9.21 inches.
Is Royal the same as US 6 by 9?
Very close. US Trade is 152 by 229 mm; Royal is 156 by 234 mm, a few millimetres larger each way. Many print-on-demand services offer both.
What is Royal used for?
Hardback non-fiction, literary hardback fiction and academic monographs.
Book Sizes
✓ Dimensions per Publishing trade size; unit values derived by formula. Reviewed . Editorial Process →