What Margins Should You Use for a B5 Thesis?

Changing a thesis template to B5 changes the amount of space available for text, but it does not tell you what margins to use. Start with your university’s formatting rules: required margins, binding allowance, and the exact paper standard override generic advice. If no specifications are provided, use a larger inner margin to keep text clear of the binding and check the result on a printed page.

Check which B5 size you need

“B5” can refer to two common page sizes:

Standard	Dimensions
ISO B5	176 × 250 mm
Japanese JIS B5	182 × 257 mm

The difference is small, but it affects the text area and can cause problems if the printer or submission portal expects a particular size. Check your school’s instructions or ask the print shop. If you cannot confirm the standard, specify the page width and height explicitly in your document rather than relying on a generic “B5” setting.

Choose margins for the finished copy

Margins are measured from the edge of the finished page to the text area. A bound thesis needs additional room at the spine: pages can curve into the binding, and some of the inner margin may be obscured. For a double-sided document, the inner edge alternates between left and right pages, so use a layout that supports mirrored margins.

If your institution gives no measurements, 35 mm inner and 25 mm outer, top, and bottom is a practical starting point for an ordinary bound B5 thesis. Treat this as a starting layout, not a universal standard. A thick hardbound copy, a required binding offset, or a printer’s trimming process may call for more inner space. Do not add a separate binding allowance on top of an already generous inner margin unless the rules call for it.

These margins leave a text block about 116 mm wide and 200 mm high on ISO B5. That is noticeably narrower than A4, so check line lengths, tables, figures, and code listings. If the text feels cramped, adjust the type size or layout only within your institution’s rules; shrinking the margins may make the printed copy harder to read or violate submission requirements.

Set B5 margins in LaTeX

The geometry package can set both the page size and the margins. This example uses ISO B5 and a two-sided layout. The inner margin includes the binding allowance; no additional bindingoffset is applied.

\documentclass[11pt,twoside]{report}
\usepackage[
  paperwidth=176mm,
  paperheight=250mm,
  inner=35mm,
  outer=25mm,
  top=25mm,
  bottom=25mm
]{geometry}

\begin{document}
\chapter{Introduction}
This thesis uses ISO B5 paper with a larger inner margin for binding.
\end{document}

The paperwidth and paperheight options remove ambiguity about which B5 size is being used. With twoside, inner and outer describe the binding and outside edges, and the package mirrors them on facing pages. The example needs no special class or additional package beyond geometry.

If you are adapting an existing thesis template, inspect its class and preamble before adding these settings. A class or a later package may already set the paper size or margins. Avoid leaving two conflicting sets of layout options in place; edit the template’s existing settings where possible. For a JIS B5 page, use paperwidth=182mm and paperheight=257mm instead.

Check the exported PDF and print

After compiling, inspect the PDF’s page properties to confirm the intended dimensions. Print one page using “Actual size” or “100%,” not “Fit to page,” which can silently scale the document. Check both a left-hand and right-hand page in a two-sided layout, and inspect the innermost text edge after binding or with a binding mock-up. Also confirm that figures, page numbers, and footnotes remain inside the printable area.

Common mistakes

• Assuming all B5 paper is the same size. Confirm ISO or JIS dimensions before setting the document or ordering prints.
• Using equal margins without checking the binding. Equal margins may leave too little usable space near the spine in a bound copy.
• Adding a binding offset twice. If your inner margin already includes the extra binding room, a second offset can make the text block unnecessarily narrow.
• Changing the PDF page size but not the printer settings. Scaling during printing changes the final margins and page dimensions.
• Relying on a generic template value. Templates are often configured for a particular university, paper size, or binding method; verify that those assumptions match your submission.