What 𝑒 means
It is an italic mathematical e; the formula tells you what it stands for. ISO style sets variables in italics and defined constants upright, including e, the base of natural logarithms. So 𝑒 is not automatically Euler's number.
The number's history is separate from this styled letter. In 1683, Jacob Bernoulli studied the limit approached as interest is added more and more often. Leibniz used the lowercase Latin b for that number in letters to Huygens in 1690 and 1691. Euler used e in a manuscript about cannon experiments written in 1727 or 1728. Why he chose e is unsettled: an available letter or a link to “exponential” have been suggested, but an homage to Euler himself is unsupported.
Why is there a separate 𝑒 character?
It preserves a mathematical style distinction in plain text. Unicode's mathematical alphabets are intended for math and technical notation, where letter style can distinguish a variable from ordinary text or another mathematical letter. They are not meant as decorative italics in ordinary prose.
Part of the collection
Don't confuse it with
1
Related characters
1
Questions people ask
2Does NFKC change 𝑒 to e?
Yes. Unicode's NFKC and NFKD compatibility-normalization modes reduce mathematical 𝑒 to plain e, losing the italic-math distinction. NFC and NFD leave it intact.
Why does 𝑒 show as a box?
It means the current font or text renderer cannot draw this mathematical letter. Try a font with mathematical-letter support; the character itself is still 𝑒.
More like this
11
How to type or find 𝑒
- Search it as
- italic e · math e · euler's number · natural logarithm base · unicode italic e
- Shows up in
- Anything that takes text · its shape is whatever your font draws
𝑒\1D4521D452 without U+ and press Alt+X.Codes and encoding1 code points
A visible symbol can contain several code points. JS .length counts UTF-16 units; UTF-8 counts bytes.