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KDP Margin Calculator

The page size and minimum margins to set for your paperback interior, based on trim size, page count and bleed.

Set page size to
Inside (gutter) margin
minimum
Outside, top and bottom
minimum
Maximum text area

In Word, use Layout → Margins → Custom Margins, set "Multiple pages" to Mirror margins, and put the gutter value in "Inside".

KDP gutter margin by page count

Page countMinimum inside margin
24–1500.375 in (9.6 mm)
151–3000.5 in (12.7 mm)
301–5000.625 in (15.9 mm)
501–7000.75 in (19.1 mm)
701–8280.875 in (22.3 mm)

Specs last checked against KDP's published specs in September 2026.

Frequently asked questions

What margins does KDP require?

The inside (gutter) margin depends on page count, from 0.375 in for up to 150 pages to 0.875 in for 701 or more pages. Outside, top and bottom margins must be at least 0.25 in without bleed, or 0.375 in with bleed.

What page size do I set in Word for KDP?

Without bleed, set the page size to your trim size, such as 6 × 9 in. With bleed, add 0.125 in to the width and 0.25 in to the height, such as 6.125 × 9.25 in.

Should I use the minimum margins?

The KDP numbers are minimums. Most novels look better with outside margins around 0.5 to 0.75 in and a gutter a little wider than the minimum.