Chord Constructions
 

The table below chords based on  C. All other chords can be deduced from the C chords.
 
Chord  Notes General Formula
C C  E  G 1 3 5
Cm C  Eb  G 1 3b 5
C7 C  E  G  Bb 1 3 5 7b
Cmaj7 C  E  G  B 1 3 5 7
Csus4 C  F  G 1 4 5
C7sus4 C  F  G  Bb 1 4 5 7b
Cm7 C  Eb  G  Bb 1 3b 5 7b
C6 C  E  G  A 1 3 5 6
Cm6 C  Eb  G  A 1 3b 5 6
Caug   (augmented) C  E  G# 1 3 5#
C dim  (diminished) C  D# F#  A 1 3b 5b 6
C - 5      (diminished fifth) C  E  F# 1 3 5b
Cadd9 C E G D 1 3 5 9
Cm9  C  Eb  G  Bb  D 1 3b 5 7b 9
Cmaj9 C  E  G  B  D 1 3 5 7 9
C9 C  E  G  Bb  D 1 3 5 7b 9
C7#9 C  E  Bb  D# 1 3 7b 9#
Miscellaneous Symbols
1. A/B means A chord with a B notes played in the lower octave (A C E + B[bass]).
Am/B means Am chord with a bass B note....and so on....

2. Sharps and Flats
C# = Db
D# = Eb
F# = Gb
G# = Ab
A# = Bb

3. Couplets
These are 2 note chords. eg. (CE) means play C and E together.
 

Deducing other chords

METHOD 1: Stepping the C based chords:

To find the notes for other chords, we use the C based chords indicated in the above table as reference, and then step up or down each note of the chord by the same number of steps (semitones) on the chromatic scale that is shown below.
 
C C# D D# E F F# G G# A A# B C C# etc...
For example, To find E7sus4, Use the formula  for C7sus4 = C F G Bb and step up each note by  4 semitones (or step down by 8 semitones) on the chromatic scale.

 Hence:
E7sus4 = E  A  B D
F7sus4 = F A# C D#

Similarly,
Am = A C E
Bm = B D F#

.... and so on for all other chords  for any of the 12 base notes of the musical scale.

METHOD 2: Using the General Formula:

It is convenient to give numbers 1 2 3 4 5 6 7 to the notes of any major scale. Then we can use the general formula to figure out any chord. Note that the flat and sharps in the notation above. e.g., 3b , does not necessarily imply a black key. It only means step down a semitone from the indicated note of the major scale. Similarly, 3# means step up a semitone. For example 7b for the A scale is the G note.
The major scales for all the 12 fundamental notes are listed below:
 
Scale
1
2
3
4
5
6
7
C major
C
D
E
F
G
A
B
C# major
C#
D#
F
F#
G#
A#
C
D major
D
E
F#
G
A
B
C#
D# major
D#
F
G
G#
A#
C
D
E major
E
F#
G#
A
B
C#
D#
F major
F
G
A
A#
C
D
E
F# major
F#
G#
A#
B
C#
D#
F
G major
G
A
B
C
D
E
F#
G# major
G#
A#
C
C#
D#
F
G
A major
A
B
C#
D
E
F#
G#
A# major
A#
C
D
D#
F
G
A
B major
B
C#
D#
E
F#
G#
A#
 
 Note that the 9th note is the same as the 2nd note, but in a higher octave.