Character Spacing Calculator

Tracking is a uniform adjustment applied to the space after every character in a run of text, as opposed to kerning, which alters one specific pair. Design software expresses it in thousandths of an em, so a tracking value of 50 means each character gains 0.050em; multiplying by the type size converts that to the pixel figure CSS letter-spacing expects, and 50 units at 16px is 0.8px. Working in em units rather than pixels matters because the em is relative to the type size, so the same tracking value keeps its proportion when text is scaled or when a responsive layout changes the size. Useful values depend strongly on size and case. Text below about 12px generally benefits from positive tracking in the 50 to 100 range because the counters and gaps close up at small sizes, body text between 14 and 18px usually needs little or nothing beyond the spacing the type designer already built in, and display sizes above roughly 24px commonly take negative tracking of -15 to -50 because inter-letter gaps look exaggerated as the type grows. All-capital settings are the clearest exception and typically want 50 to 200 units, since capitals were drawn to be spaced apart. The limits are real: tracking cannot fix badly fitted type, heavy positive tracking destroys the word shapes fluent readers rely on, and because tracking widens every character it changes copyfit - the extra width equals character count times the per-character increment, which can add lines and pages.

Letterspacing existed in metal composition but was slow and coarse: a compositor inserted thin brass or copper spaces, usually one point or less, by hand between sorts, so uniform tracking across a paragraph was expensive enough to be reserved for capitals, small caps and fine display work. That cost is the background to the trade maxim, attributed to the American type designer Frederic Goudy, that anyone who would letterspace lowercase would commit almost any other outrage - a joke that survives because the practice was both laborious and usually a sign of poor fitting. Phototypesetting in the 1960s and 1970s made continuous spacing adjustment cheap, since character images were projected onto film and the advance between them could be varied by any amount, and machines of that era introduced the tight settings characteristic of the period's advertising typography. Digital page-layout software inherited the idea and fixed the unit: Adobe applications settled on a scale of one thousandth of an em, which is why tracking values are entered as whole numbers such as 20 or -30 rather than decimals, and why the conversion to CSS is a division by 1000. On the web, letter-spacing was part of CSS from the first Cascading Style Sheets Level 1 Recommendation in 1996, and the current CSS Text specification defines it as spacing inserted between typographic character units, accepting negative values as well as positive.