Alternative classes

When the standard classes (article, report, book) do not give you enough control over the design, the two big “do-everything, highly configurable” class families you reach for are KOMA-Script and memoir. The first is a set of drop-in replacements with refined Western typography; the second is an all-in-one book/report class that folds the functionality of many packages into one. This page covers what each is, the key levers for configuring them, and when to choose which.

Why replace the standard classes

article / report / book are mature and reliable, but the moment you want to change their default margins, headings, or headers and footers, you tend to end up patching internal commands behind \makeatletter or stacking several helper packages — geometry, fancyhdr, titlesec, tocloft. The details of the standard classes themselves belong to the Standard classes page; the point here is that they offer little design freedom and few sanctioned entry points for change.

KOMA-Script and memoir answer that frustration head-on. Both serve as replacements for the standard classes, and both ship with sanctioned commands and options for changing the design from the start. Where they differ is in origin and philosophy: KOMA-Script is “replacement classes with good typography plus a configuration mechanism,” while memoir is “a monolithic book class that absorbs whole helper packages.”

KOMA-Script — the replacement classes

KOMA-Script is a bundle of LaTeX2ε classes and packages developed and maintained by Markus Kohm (copyright 1994–2026; version 3.49.2 at the time of writing, released 2026-02-02), built mainly around drop-in replacements for the standard classes. **scrartcl** corresponds to article, **scrreprt** to report, and **scrbook** to book, with a dedicated **scrlttr2** for letters. You write the body much as before (\section, \chapter, and so on), but the default typography is more polished and the hooks for configuration are wide open.

You configure it in one of two ways: pass options as class options to \documentclass[...]{scrartcl}, or change them after loading with **\KOMAoptions{...}**. KOMA-Script provides the ability to change the values of most options even after the package is loaded; \KOMAoptions takes a comma-separated list of option=value settings at once. When a single option needs several values simultaneously, use **\KOMAoption{option}{val1,val2}**.

The type area — DIV and BCOR

At the heart of KOMA-Script’s page design is the **typearea** package (loaded automatically when you use a KOMA class, so you should not add \usepackage{typearea} yourself). Instead of giving margins directly in millimetres, it divides the page into a number of strips horizontally and vertically and derives the typeblock and margins from those proportions — an approach rooted in the practice of the typographer Jan Tschichold.

The number of strips is set by **DIV=**. As the manual puts it, “the DIV=factor option specifies the number of strips into which the page is divided horizontally and vertically during the construction of the type area,” and the key fact is that the larger the factor, the larger the text block and the smaller the margins — so more text fits on a page. Any integer greater than 4 is valid for factor. On A4 the default tracks the body size: 8 for 10pt, 10 for 11pt, 12 for 12pt. To have the value computed automatically for your font use DIV=calc; for the traditional “medieval page canon” look use DIV=classic.

The other is **BCOR=** (binding correction — the gutter). You give it the width lost into the spine during binding; that amount is subtracted from the type-area calculation and then added back to the inner (left) margin on output. The value may use any unit TeX understands (for example BCOR=10mm). Changing DIV or BCOR via \KOMAoptions automatically recalculates the type area and margins.

\documentclass[DIV=12,BCOR=10mm]{scrartcl}
% DIV=12  本文ブロックを広めに（A4・12pt 既定と同じ分割数）
% BCOR=10mm  綴じ代 10mm を内側余白へ確保
\usepackage[T1]{fontenc}
\usepackage{microtype}

\title{A Short Report}
\author{Ada Lovelace}

\begin{document}
\maketitle
\section{Introduction}
KOMA-Script keeps the body markup of \textsf{article}
while giving you DIV and BCOR for the page layout.
\end{document}

One caveat when you load a font package later: writing DIV=calc as a class option fixes the layout for the standard font, before yours is loaded. After changing the font, call \KOMAoptions{DIV=last} (or DIV=current) in the preamble to recalculate for the new font.

Tuning KOMA — element fonts and headings

KOMA-Script lets you set the font for each document element — headings, captions, and so on — in one place. **\setkomafont{element}{commands} gives that element a completely new font definition, while \addtokomafont{element}{commands}** merely extends the existing one (and \usekomafont{element} switches the current font to that element’s). The commands should be limited to things that only change font attributes, such as \sffamily, \bfseries, or \Large, and both are declared in the preamble.

To rework the design of a sectioning command itself — the space before and after, its font, how its number is shown — use **\RedeclareSectionCommand[attributes]{name}**. This is the sanctioned entry point for redefining the attributes of an existing sectioning command (\section, \chapter, …) via a comma-separated list of key=value settings. For headers and footers, the recommended companion is the **scrlayer-scrpage** package, whose commands like \lehead, \cohead, and \rohead let you set each “left/centre/right” × “even/odd page” slot independently.

memoir — the all-in-one book class

memoir is a class first released by Peter Wilson in 2001 and now maintained by Lars Madsen. Its hallmark is that it **builds on the standard book class and integrates the functionality of many design-related packages into one** — in the author’s words, it “includes the functionality of many packages, for instance the tocloft package for controlling the table of contents or methods similar to the fancyhdr package for designing your own headers” (it does not touch mathematics or the territory of babel/hyperref). It serves as a replacement for the book and report classes — by default producing documents virtually indistinguishable from them — yet offers options for an article-like look and, above all, is designed with tweaking very much in mind.

You assemble the page layout with dedicated commands. **\setlrmarginsandblock{spine}{edge}{ratio} sets the left/right (spine and fore-edge) margins, holding the page width fixed while the typeblock width follows from them. \setulmarginsandblock{upper}{lower}{ratio}** sets the upper and lower margins the same way. In each, the third argument is a ratio, and you may put * for a value you would rather have computed.

Crucially, these specifications do nothing on their own. The layout takes effect only when you call **\checkandfixthelayout** (per the manual: “unless you are satisfied with the default page layout, after specifying the layout that you want you have to call the \checkandfixthelayout command to finally implement your specification”). Chapter-heading design is switched with **\chapterstyle{style}** — like \pagestyle, it sets the style of subsequent chapter headings — and many predefined styles ship with it: default (the familiar book look), section (number and title on one line), hangnum (chapter number hung in the margin), companion (the LaTeX Companion look), and more. It is an especially popular class for book design.

\documentclass[11pt,a4paper,twoside]{memoir}

% --- page layout (must end with \checkandfixthelayout) ---
\setlrmarginsandblock{30mm}{25mm}{*}  % spine, fore-edge
\setulmarginsandblock{30mm}{35mm}{*}  % upper, lower
\checkandfixthelayout

\chapterstyle{hangnum}

\begin{document}
\chapter{Beginnings}
memoir bundles page layout, headers, and chapter styles
into one configurable book class.
\end{document}

Which to choose, and when

KOMA-Script and memoir overlap in aim, and either can produce high-quality documents. As a rule of thumb, reach for KOMA-Script for a natural step up from the standard classes — papers and reports — when you want polished default typography and the clear page control of DIV/BCOR. Reach for memoir when designing a single book down to the details, since layout, headers, chapter styles, and the table of contents all live inside one class. Their philosophies differ, so do not mix them — pick one per document.

That said, for documents that are mostly Japanese, classes specialised for Japanese typesetting are the baseline instead. Japanese line spacing, kinsoku (line-break prohibition), and inter-character spacing are the province of dedicated classes — jsarticle / jsbook (jsclasses), their LuaLaTeX counterparts ltjsarticle / ltjsbook, or the newer jlreq. Treat KOMA-Script and memoir as choices for Western-language documents, distinct in purpose from the Japanese classes. And if your goal is slides, the separate beamer class is the standard.