Book sizes and photo sizes
Books and photos do not follow the A series. They still have fixed sizes: a UK B-format paperback is 129 × 198 mm, the most common photo print is 6 × 4 inches (10 × 15 cm), and American books often come out at 6 × 9 inches.
Contents of this page
All pages on books and photos
- Book sizesUK paperback formats A, B and C, Demy and Royal hardbacks and German book sizes in mm, plus folio, quarto and octavo and where they come from.
- US trim sizesStandard US book trim sizes from mass market to 8.5 × 11 inches with millimetres, and what to know when self-publishing.
- Photo print sizesStandard photo print sizes in centimetres and inches, aspect ratios 3:2 and 4:3, the pixels you need and how to avoid cropped prints.
- Film and sensor formatsAnalogue film formats from 35 mm to large format and digital sensor sizes from 1 inch to medium format, with dimensions and crop factors.
Why books do not use A sizes
Book sizes are older than any standard. They grew out of the size of press sheets and the way those sheets were folded, and every publisher has its own habits. Binding machines are set up for these sizes, and readers expect a novel to be a certain size. A novel in A4 would look odd. A5, on the other hand, is a popular size for workbooks, notebooks and self-published titles.
Why photos are 6 × 4 inches
A 6 × 4 inch print, or 10 × 15 cm in Europe, has an aspect ratio of 3:2, just like a 35 mm film negative at 24 × 36 mm. A print therefore shows the whole picture with nothing cropped. Smartphones, however, usually shoot at 4:3. Order those images as 6 × 4 prints and you lose a strip at the top and bottom. More on photo print sizes.
Frequently asked questions
Is there a standard for book sizes?
No. Book sizes developed over centuries and differ from publisher to publisher. Most sit between A6 and A4.
What aspect ratio is a 6 × 4 photo?
3:2, the same as 35 mm film.