What are the possible dimensions / sizes / units LaTeX understands?

From the plain TeX reference:

  • pt: Point
  • pc: pica (12 pt)
  • in: inch (72.27 pt)
  • bp: Big point (72 bp = 1 in)
  • cm: Centimeter
  • mm: Millimeter
  • dd: Didot point (1157 dd = 1238 pt)
  • cc: cicero (12 dd)
  • sp: Scaled point (65536 sp = 1 pt), the smallest TeX unit
  • ex: Nominal x-height
  • em: Nominal m-width

Available in math mode:

  • mu: math unit, 1 em = 18 mu, where em is taken from the math symbols family, various lengths are derived from it (thinspace, thickspace, etc.)

Additionally available in pdfTeX and LuaTeX:

  • px: "pixel", the dimension given to the \pdfpxdimen primitive; default value is 1 bp, corresponding to a pixel density of 72 dpi

See also here on TeX.SX:

  • What are the various units (ex, in, pt, etc.) expressed in mm?
  • Conversion pt to mm or cm
  • Which measurement units should one use in LaTeX?

The meanings of the various points are described here:

  • Wikipedia: Point (typography)

I made visual overview for all units available in TeX. Including a comparison and the definitions/conversions.

previwe

The complete code and PDFs (EN, DE; b/w, color) are available at GitHub: https://github.com/tweh/tex-units