What is the key signature of E flat major? How many flats are in the key of E flat major? Here is the answer:
The key signature of E flat major has three flats : B flat, E flat and A flat (B♭, E♭ and A♭)

Position of flats in all clefs
The flats are positioned according to the clefs, here is E flat major key signature in all clefs:

E flat major key signature in treble clef (G-clef)

E flat major key signature in bass clef

E flat major key signature in baritone clef

E flat major key signature in tenor clef

E flat major key signature in alto clef

E flat major key signature in mezzo-soprano clef

E flat major key signature in Soprano clef
How to find E flat major key signature?
If you only know the name of the key and you want to know how many accidentals there are in this key, how would you do to find the key signature? I will explain it to you:
To find the E flat major key signature, there are two methods: The circle of fifths or your brain .
With the circle of fifths:
Finding E♭ major key signature with the circle of fifths is very easy, you just had to read the circle:
Major keys are in the colored parts of the circle, just find E♭ and read how many flats they are: three flats!
With your brain and rules of music theory:
- Major scales with the word flat (♭) have key signatures with flats, so E flat major has one or several flats.
- You already know perfectly the order of flats: B♭ E♭ A♭ D♭ G♭ C♭ F♭
- The second to last flat (♭) of the key signature is always the degree I of the scale, and degree I is also the name of the key:
- So if E♭ is the second to last flat, so A♭ is the last.
Conclusion: The key signature of E flat Major contains 3 flats (3♭) : B♭, E♭ and A♭