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Cover Size Calculator

Calculate book cover dimensions for hardcover and paperback binding. Includes spine width, bleed margins, and board wrap allowances for print.

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Inputs that matter
Text Block Width, Text Block Height, Spine Width, Overhang (fore-edge)
Output to expect
Cover Board Size
  • Check the units and required inputs before comparing results.
  • Keep the assumptions with a copied result so you can reproduce the calculation later.
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Reference & details

How it works

Hardcover Flat Cover

Turn-in (board wrap): typically 0.75–1 inch per side. Add bleed (0.125 in standard) on all outer edges.

Width = (2 × Trim width) + Spine + (2 × Turn-in) + Bleed

Paperback Cover

Paperback wraps without turn-in. Spine width from Spine Width Calculator. Bleed on three sides (spine side may not bleed).

Width = (2 × Trim width) + Spine + Bleed

Cover Height

Hardcover turn-in wraps over board top and bottom. Paperback extends only for bleed trim.

Height = Trim height + (2 × Turn-in) + Bleed (hardcover) | Trim + Bleed (paperback)

Updated: July 2026

Example Scenarios

Flat cover: (2×6) + 0.5 + (2×0.75) + 0.25 bleed = 14.25 inches wide × 10.5 inches tall.

Spine 0.42 in. Cover width: (2×5) + 0.42 + 0.25 = 10.67 inches. Height: 8.25 inches with bleed.

Dust jacket extends 2–3 inches beyond cover on all sides with flaps folding inside — calculate separately from case cover.

FAQ

Turn-in is the cover material wrapped over the edge of board covers — typically 0.75–1 inch. It covers board edges and attaches to endpapers inside.

Standard print bleed is 0.125 inches (3mm) on all trimmed edges. Background colors and images must extend into bleed area.

Yes. Spine text area equals calculated spine width minus 0.1 inch safety margin on each side. Text on spines narrower than 0.25 inch is often omitted.

Add 0.25–0.5 inch per side between spine and front/back cover panels for the hinge groove where cover bends.

No. Hardcover includes turn-in and hinge dimensions. Paperback is smaller overall. Recalculate for each binding type.

About Cover Size Calculator

Book covers must precisely wrap the text block with correct spine width and board overhang. Enter trim size, spine width, binding type, and bleed to calculate total cover flat dimensions for printing.