Reference
Web Typography Glossary
Definitions of core typography terms for developers — measure, leading, contrast ratio, type scale, and font weight — with links to interactive lessons.
These terms appear throughout Grade lessons. Each definition explains why the concept matters for web readability and links to the lesson where you can experiment with it.
- Measure — In typography, measure is the width of a text column — how many characters fit on one line. On the web, it is controlled…
- Leading — Leading is the vertical space between lines of type. Named after lead strips in letterpress printing, it maps directly t…
- Contrast ratio — Contrast ratio is a numerical measure of luminance difference between foreground and background colors, expressed as X:1…
- Type scale — A type scale is a set of font sizes generated by multiplying a base size by a consistent ratio at each step — for exampl…
- Font weight — Font weight is the stroke thickness of a typeface, specified in CSS from 100 (thin) to 900 (black). 400 is regular body …
Start learning
New to web typography? Begin with the web typography guide or jump to the measure lesson on line length.