'tis easy...
Fractions.
1/1 = open string - Fundamental
1/2 = at the 12th fret (for fretted instruments) - Octave
1/3 - Octave + Perfect Fifth
1/4 - two Octaves
1/5 - two Octaves + Major Third
1/6 - two Octaves + Perfect Fifth
1/7 - two Octaves + Minor Seventh
1/8 - three Octaves
1/9 - three Octaves + Major Second
1/10 - three Octaves + Major Third
1/11 - three Octaves + Augmented Fourth
1/12 - three Octaves + Perfect Fifth
1/13 - three Octaves + Major Sixth
1/14 - three Octaves + Minor Seventh
on and on...
The Fundamental through the 14th harmonic (fundamental being the 1st), gives you a Dominant 13 +11 chord.
Ex.: Using the Open G-String, the harmonics ascend (see above list):
G, G, D, G, B, D, F, G, A, B, C#, D, E, F
All the notes found in a G13(+11).