line spacing120–145% of the point size

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 held over from the type­writer era. Orig­i­nal­ly, a type­writer’s car­riage could only move ver­ti­cal­ly in units of a sin­gle line. There­fore, line-spac­ing choic­es were lim­it­ed to one, two, or more lines at a time. Dou­ble-spac­ing be­came the de­fault be­cause 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

Word Right-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.

Pages ’09 In­spec­tor (com­mand + op­tion + i) T icon in the top row (fourth from left) Text. Un­der Spacing and Line, there’s a slid­er. Find the pop­up menu next to the slid­er. Exactly is best—en­ter a fixed mea­sure­ment. You can also use the Multiple op­tion, but like Word, it adds ex­tra space—about 17%. There­fore, to get line spac­ing in the 120–145% range, use a Multiple val­ue of 1.03–1.29. Avoid the oth­er options.

CSS Use the line-height property

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 has a much more sig­nif­i­cant ef­fect on the length of a doc­u­ment than point size. If you need to fit a doc­u­ment onto a cer­tain num­ber of pages, ad­just the line spac­ing first.