What is the amount of vertical space between the lines of text in a paragraph called?

Use the line-height property in CSS to do so.

Browsers by default will create a certain amount of space between lines to ensure that the text is easily readable. For example, for 12-point type, a browser will place about 1 point of vertical space between lines. The space between lines of text is called the leading, a term loosely inherited from print publishing.

Line-height uses the standard CSS units of measurement, just like letter-spacing. You can designate text to have 26 points of leading like this:

The text in this paragraph would have 26 points of leading.

Relative measurements are best with line-height, however, because they will work with any size of type. For example, you can create text with the word processor equivalent of 1.5 lines like this:

.oneandhalf {line-height: 1.5em;}

The text lines in this paragraph would have 1.5 lines of spacing regardless of font size.

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 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.

The amount of vertical space between lines of type is referred to as line spacing or leading. The latter term dates back to the days of metal type, when lead strips of varying thicknesses were inserted between lines of type to create space.

Without this leading, type was [and still is] described as being set solid. In today’s digital world, the adjustment of line spacing is made much more easily – with the click of a mouse.

Line spacing is measured from baseline to baseline. In print, it is traditionally measured in points [or as normal, double and triple in some word processing programs].

But for the web and digital devices, it is commonly referred to as line height, and can be expressed in pixels, points or centimeters [px, pt or cm], or as a percentage of the type size [120% or 1.2]. Other accepted terminology includes normal, small and big.

The many differences between an unkerned setting [upper] and one that has been kerned [lower] can clearly be seen here.

Even at the same type size, line spacing will vary from typeface to typeface. The Bernhard Modern™ typeface [left], with its short x-height, looks fine at 15/16 point, but the Baskerville™ eText design [middle] has a much larger x-height, making it appear cramped at the same size and leading. Its readability is greatly improved when the line spacing is increased to 20 points while keeping the type size the same [right].

Regardless of media or output – print or digital, line spacing remains an extremely important aspect of setting inviting, readable text. In most instances, generous line spacing helps the eye and brain to more easily decipher the character shapes, words and word groupings, which is how we read.

The smaller the type size, the greater the line spacing needed, proportionally speaking, to offset the reduced readability of small settings. Other factors affecting line spacing are the x-height of a typeface, as well as the cap height at a given point or pixel size, which can vary from typeface to typeface. The taller the x-height [and, correspondingly, the shorter the ascenders and descenders], the more line spacing is needed to maintain good readability and prevent the setting from looking cramped.

Most design software programs include a default line spacing setting that is typically 120% of the type size [although it is possible to change the default setting]. While the default formula can be a useful time-saver when experimenting with setting text at various sizes, the best end result will be achieved by deciding on a fixed value selected for the size of type ultimately used in the specific layout.

The Malabar™ eText design looks quite cramped when set with auto leading, 14/16.8 point. It becomes much easier to read when line spacing is increased, making it 14/21 point.

When text is set solid [upper] – even at a generous point size – it can be difficult to read, as illustrated in this setting of the Metro® Nova typeface at 18/18. Reducing the size of the type while keeping the line spacing the same [13/18], makes the text much easier to read, even at a smaller type size [lower]. 

Download the Line Spacing For Text Article