Line spacing is the vertical distance between lines of text. Most writers use either double-spaced lines or single-spaced lines—nothing in between—because those are the options presented by word processors.
These habits are obsolete typewriter habits. Originally, a typewriter’s platen could only move the paper vertically in units of a single line. Therefore, line-spacing choices were limited to one, two, or more lines at a time. Single-spaced typewritten text is dense and hard to read. But double-spacing is still looser than optimal.
For most text, the optimal line spacing is between 120% and 145% of the point size. Most word processors, as well as CSS, let you define line spacing as a multiple. Or you can do the math—multiply your point size by the percentage. (The text in this paragraph has line spacing of 110%. It’s too tight.)
For most text, the optimal line spacing is between 120% and 145% of the point size. Most word processors, as well as CSS, let you define line spacing as a multiple. Or you can do the math—multiply your point size by the percentage. (The text in this paragraph has line spacing of 135%. It looks fine.)
For most text, the optimal line spacing is between 120% and 145% of the point size. Most word processors, as well as CSS, let you define line spacing as a multiple. Or you can do the math—multiply your point size by the percentage. (The text in this paragraph has line spacing of 170%. It’s too loose.)
Word processors have a bewildering number of ways to set line spacing. Don’t be thrown off—it all comes back to the same thing.
How to set line spacing
WordRight-click in the text and select Paragraph from the menu. Go to the menu under Line spacing. Exactly is best—enter a fixed measurement. Single, 1.5 lines, and Double are equivalent to about 117%, 175%, and 233% line spacing, contrary to what their names suggest. Don’t use these—they miss the target zone of 120–145%. Multiple is also acceptable—enter line spacing as a decimal. To get line spacing in the 120–145% range, use a Multiple value of 1.03–1.24. (Not 1.20–1.45—as noted above, Word uses peculiar line-spacing math.) Never use At least, because that gives Word permission to adjust your line spacing unpredictably.
PagesView → Show Toolbar (or option + ⌘ + t) → Format button → Style pane → under Spacing, there’s a popup menu. Exactly is best—enter a fixed measurement. You can also use the Lines option, but like Word, it adds extra space—about 17%. Therefore, to get line spacing in the 120–145% range, use a Lines value of 1.03–1.29. Avoid the other options.
CSSUse the line-height property, preferably without units (here’s why)
by the way
Recall that different fonts set at the same point size may not appear the same size on the page. (See point size for why.) A side effect is that fonts that run small will need less line spacing, and vice versa.
Line spacing affects the length of a document more than point size. If you need to fit a document onto a certain number of pages, try adjusting the line spacing first.