The E eleventh chord is a 5-note chord consisting of the notes E, B, D, F# and A.
You can see these notes highlighted in the interactive piano chart below.
The chord itself is often abbreviated as E11.
Chords that are a superset of E11. The chords include more notes but always E, B, D, F# and A.
Chords that are a subset of E11. These contain less notes but all of them are included in E11.
In case you prefer a non-interactive variant of the chord chart, we've embedded a PNG image below that shows the notes for the the E11 chord. Feel free to save or share the image as needed.