Cap height is the height of capital letters, measured from the baseline to the top of a flat letter such as “H”. Together with the x-height, it sets the main vertical proportions of a typeface.
Where to see it
Cap height is measured on flat-topped capitals such as “H”, “E”, “I” or “T”. Round or pointed capitals, such as “O” or “A”, overshoot it very slightly so that they appear the same size, and in many typefaces the ascenders of lowercase letters rise a little higher than the cap height.
Why this detail matters
Cap height directly shapes the balance and look of a typeface:
- The ratio between cap height and x-height determines the presence of capitals in the text: discreet when the gap is small, more assertive when it is large;
- Capitals slightly shorter than the ascenders blend more harmoniously into running text, without creating visual peaks;
- Aligning the cap heights of several fonts is essential for composing headlines, logos or interfaces that look crisp and balanced.
Related term
The x-height is the height of lowercase letters without ascenders or descenders, measured from the baseline to the top of the “x”.
Anatomy glossary
Ascender, Descender, Sidebearing, Joint, Axis, Bar, Beak, Bowl, Loop, Set width, Counter, Serif, Stem, Leg, Minim, Baseline, Eye, Belly, Foot, Point, Tail, Cross stroke, Terminal; X-height, X-height, Cap height, Body; Mean line, Ear, Spur, Ball terminal, Ligature, Apex, Vertex, Arm, Shoulder, Spine, Em dash, Thick stroke, Hairline, Bracket, Bounding box