The following chart lists chord formulas for the 8 most common keys used by lead guitarists. Other chords not listed can be derived by applying the correct formula to the respective scale, e.g.:
B7 is based on the dom 7 formula (I - III - V - VII) and the B scale:
*The Roman numerals written beneath each chord can be useful when transposing these 25 chords to other keys. Each Roman numeral indicates the relative note of the major scale, e.g., in the key of C, I is C major, IIIm is E minor etc. In the key of E, I is E major, IIIm is G# minor etc.