point sizeSmaller on paper; bigger on screen

In print, the op­ti­mal point size for body text is 10–12 point. On the web, the op­ti­mal size is 15–25 pixels.

Point size in print

Though 12 point has be­come the de­fault size in dig­i­tal word pro­cess­ing—and also the ba­sis of many in­sti­tu­tional doc­u­ment-for­mat­ting rules—that’s mostly due to the type­writer tra­di­tion. It’s not the most com­fort­able size for read­ing. Nearly every book, news­pa­per, and mag­a­zine is set smaller than 12 point. (One ma­jor rea­son is cost: big­ger point sizes re­quire more paper.)

If you’re not re­quired to use 12 point, don’t. Try sizes down to 10 point, in­clud­ing in­ter­me­di­ate sizes like 10.5 and 11.5 point—half-point dif­fer­ences are mean­ing­ful at this scale.

But I can’t guar­an­tee 12 point will al­ways look too big. That’s be­cause the point-size sys­tem is not ab­solute—dif­fer­ent fonts set at the same point size won’t nec­es­sar­ily ap­pear the same on the page.

So you need to let your eyes be the judge. Don’t just rely on the point size. For in­stance, the three fonts be­low—Sabon, Times New Ro­man, and Arno—are set at 12 point, but they’re not the same size visually.

You can match the length of two fonts by set­ting a block of text twice: once in the old font and once in the new font, both at the same point size. Ad­just the point size of the new font un­til each line of text breaks in roughly the same place. (You won’t be able to match them ex­actly.) Be­low, the point sizes of Sabon and Arno have been ad­justed so they oc­cupy the same space as Times New Roman.

The point size can be even smaller in pro­fes­sion­ally type­set ma­te­ri­als like pub­li­ca­tions and sta­tionery. Text on busi­ness cards is of­ten only seven or eight points. All caps text is of­ten just as leg­i­ble as reg­u­lar low­er­case text at these sizes.

It’s fine to em­pha­size text with a larger point size (or de-em­pha­size it with a smaller point size). But com­pared to bold or italic, or all caps, point size of­fers a sub­tle range of ad­just­ments. So use the sub­tlety. In print, if your text is set at 11 point, you don’t need to go all the way to 14 point for em­pha­sis. Start with a small in­crease—say, half a point—and move up in half-point in­cre­ments un­til you get the em­pha­sis you need. It’ll be less than you think.

Point size on the web

For web­sites, I rec­om­mend body text of 15–25 pix­els. As with print, you’ll need to fine-tune based on the par­tic­u­lar font you’re using.

Why? Two rea­sons. First, we typ­i­cally read screens from fur­ther away than we read printed ma­te­r­ial, so larger point sizes help com­pen­sate. Sec­ond, screen fonts are ren­dered with a rel­a­tively small num­ber of pix­els, so each ex­tra row of pix­els im­proves the quality.

Yes, I know the web has a long tra­di­tion of teeny fonts. It’s time to let it go. This habit arose be­cause the 14-inch mon­i­tors com­mon in the 1990s had rel­a­tively coarse res­o­lu­tion. It per­sisted be­cause web de­sign­ers con­sid­ered it vir­tu­ous to keep ac­com­mo­dat­ing peo­ple who re­fused to up­grade those 14-inch mon­i­tors. But now, it’s merely silly.

Also silly is the web’s tra­di­tion of enor­mous point sizes for head­ings. This habit started with the de­fault for­mat­ting of <h1> tags in browsers, which is about 200% of the de­fault point size of body text. There is no ty­po­graphic uni­verse in which you need to dou­ble the point size to achieve em­pha­sis. See head­ings for sub­tler techniques.

For more about the en­trenched ty­po­graphic habits of the web, see web­sites.

by the way
  • In hy­phens and dashes, I men­tioned that em refers to a ty­pog­ra­pher’s mea­sure­ment, not the let­ter M. The em size of a font is the same as its point size. Fonts are no longer made of metal, but the em con­cept per­sists. Dig­i­tal fonts are drawn in­side a rec­tan­gle called the em. To ren­der a font on screen, your com­puter scales the em to match the cur­rent point size. Two fonts set at the same point size will ap­pear to be dif­fer­ent sizes if one oc­cu­pies less space on its em.

  • Can you de­ter­mine the point size of a font by mea­sur­ing it? No. Be­cause of the dif­fer­ences in ap­par­ent siz­ing be­tween fonts, there’s noth­ing you can mea­sure that would be con­clu­sive. The only way to fig­ure it out is to set the same text, in the same font, with the same line length. Then ad­just the point size so it matches the ref­er­ence sample.

  • As you re­duce point size, also re­duce line spac­ing and line length. For in­stance, news­pa­per fonts are quite small, but re­main leg­i­ble be­cause they have snug line spac­ing and short line length.

  • Or­ga­ni­za­tions that need to con­trol the length of doc­u­ments (e.g., courts, col­leges) usu­ally do so with lim­its on point size and page length. In the type­writer age, this worked be­cause type­writer out­put was stan­dard­ized. In the dig­i­tal age, it makes less sense, since art­ful for­mat­ting and lay­out can make doc­u­ments ap­pear longer or shorter as nec­es­sary. Any­one who needs to set stan­dards for doc­u­ment length would be bet­ter off putting these rules in terms of word count. Un­like type­writ­ers, all word proces­sors have a word-count func­tion. Com­pared to page lim­its, word counts are harder to evade. To be fair, they’re also harder to verify.

  • In 2012, a dis­pute about point size reached the Michi­gan Supreme Court. One side ar­gued—con­trary to 400 years of ty­po­graphic cus­tom—that a law call­ing for “14-point type” on a bal­lot meant that the up­per­case let­ters of the font had to be at least 14 points tall. For­tu­nately the court did not adopt this in­ter­pre­ta­tion, which would’ve re­de­fined the mean­ing of point size through­out the state.