How do I calculate cloth size for a hardcover book?

The cloth must wrap around both boards, the spine and fold over all four edges. Width = (board width x 2) + spine width + (hinge gap x 2) + (turn-in x 2). Height = board height + (turn-in x 2). Standard turn-in is 15-20 mm.

What board thickness should I use for a hand-bound book?

For A5 books, 1.5-2 mm greyboard is standard. A4 and larger books need 2-3 mm. Board weight affects how the book opens — too heavy and it will not lie flat. Lighter board (1 mm) is suitable for soft journals and notebooks.

How many signatures do I need?

A standard sewn binding uses signatures of 4 sheets (16 pages each). Divide your total page count by 16 and round up. Thicker paper (over 120 gsm) may need 3 sheets per signature to fold cleanly. Thin paper can take 5-6 sheets per signature.

What paper weight works best for bookbinding?

For text pages, 80-120 gsm is ideal. Heavier papers (150+ gsm) make thick spines and do not fold well in signatures. For sketch and art books, 140-200 gsm is common but keep the page count lower. Endpapers are typically 120-150 gsm.

CraftCalcs

Bookbinding Calculator — Paper, Board, Cloth & Spine

Calculate paper, board, cloth, and spine dimensions for hand-bound books.

Total Pages

Total page count (should be divisible by 4)

Page Width

Width of each page (e.g. 148 for A5)

Page Height

Height of each page (e.g. 210 for A5)

Paper Weight

Paper weight in grams per square metre

Binding Style

Affects board overhang and cloth calculation

Board Thickness

Greyboard thickness for covers

How We Calculate This

Spine Width

Spine = Leaf count x Paper thickness

Paper thickness (mm) = GSM x 0.001 (approximate)

Board Size

Board = Page size + Overhang (3 mm overhang on three sides for case binding)

Cloth Size

Width = (Board width x 2) + Spine + (Hinge x 2) + (Turn-in x 2)

Height = Board height + (Turn-in x 2)

Frequently Asked Questions

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Last updated: March 2026

All calculations are estimates. Always verify quantities before purchasing materials.