In many proportional fonts, numerals (i.e. 0123456789) have identical width to facilitate vertical alignment. My question is simple: are there any characters that conventionally share the exact same width as these ten? For example, I’ve found one font where the ‘=’ character is the same width as the numerals:
0000000000
1111111111
2222222222
3333333333
4444444444
5555555555
6666666666
7777777777
8888888888
9999999999
========== <- sometimes same as numerals
mmmmmmmmmm <- nearly always wider
llllllllll <- nearly always narrower
Answer
The answer to the question “Are there any characters that conventionally share the exact same width as these ten?” is a qualified “Yes.”
Tabular numerals (whether Lining or Oldstyle) are the default in most fonts. They are designed for tables, as in balance sheets, annual reports and similar financial applications. In any given table, the only things that MUST have the same width are the numerals, so only these are designed that way. In most modern typefaces, #, $ and other currency symbols are given the same width as tabular numerals, but nothing else. Even the # and the British pound symbol (which map to the same ASCII number in the old 7-bit code) can be much wider in older typefaces like Baskerville, so this isn’t a universal standard.
If you have an OpenType font, look in the Glyphs panel in AI or ID or a similar application for the Lining Figures section. Most of the glyphs (not all) in that section will have the same set width as the numerals. Beyond that, if a given glyph in a particular font happens to have the same set width as a tabular numeral, it is a coincidence. (The equals sign you found is an example.)
Attribution
Source : Link , Question Author : paperjam , Answer Author : Alan Gilbertson