Harp strings are generally identified by their octave and pitch:
Middle C is the 4th octave C.
String Measurements
To work out which strings you need:
Nylon String Diameters
| Pitch | Pedal Diamater (mm) | Lever Diamater (mm) |
| Octave 0 | ||
| G | 0.51 | - |
| F | 0.51 | - |
| 1st Octave | ||
| E | 0.54 | 0.51 |
| D | 0.58 | 0.51 |
| C | 0.60 | 0.54 |
| B | 0.63 | 0.58 |
| A | 0.66 | 0.58 |
| G | 0.68 | 0.60 |
| F | 0.71 | 0.63 |
| 2nd Octave | ||
| E | 0.74 | 0.66 |
| D | 0.76 | 0.68 |
| C | 0.79 | 0.74 |
| B | 0.82 | 0.74 |
| A | 0.84 | 0.82 |
| G | 0.88 | 0.84 |
| F | 0.94 | 0.94 |
| 3rd Octave | ||
| E | 0.99 | 0.94 |
| D | 1.05 | 0.94 |
| C | 1.10 | 1.05 |
| B | 1.14 | 1.05 |
| A | 1.18 | 1.05 |
| G | 1.25 | 1.14 |
| F | 1.32 | 1.18 |
| 4th Octave | ||
| E | 1.36 | 1.18 |
| D | 1.42 | 1.25 |
| C | 1.47 | 1.32 |
| B | 1.55 | 1.32 |
| A | 1.67 | 1.36 |
| G | 1.74 | 1.42 |
| F | 1.81 | 1.42 |
Gut (Bow and Burgundy) String Diameters and Lengths
| String number | Pitch | Pedal Diameter (mm) | Lever Diameter (mm) | Length (cm) |
| 1st Octave | ||||
| 1 | E | 0.56 | 0.47 | 122 |
| 2 | D | 0.58 | 0.50 | 122 |
| 3 | C | 0.60 | 0.52 | 122 |
| 4 | B | 0.62 | 0.54 | 122 |
| 5 | A | 0.64 | 0.56 | 122 |
| 6 | G | 0.66 | 0.58 | 122 |
| 7 | F | 0.68 | 0.60 | 122 |
| 2nd Octave | ||||
| 8 | E | 0.70 | 0.62 | 122 |
| 9 | D | 0.73 | 0.64 | 122 |
| 10 | C | 0.76 | 0.66 | 122 |
| 11 | B | 0.80 | 0.68 | 122 |
| 12 | A | 0.85 | 0.70 | 122 |
| 13 | G | 0.88 | 0.73 | 122 |
| 14 | F | 0.92 | 0.76 | 122 |
| 3rd Octave | ||||
| 15 | E | 0.95 | 0.80 | 122 (lever), 152 (pedal) |
| 16 | D | 1.00 | 0.85 | 122 (lever), 152 (pedal) |
| 17 | C | 1.05 | 0.90 | 122 (lever), 152 (pedal) |
| 18 | B | 1.10 | 0.95 | 122 (lever), 152 (pedal) |
| 19 | A | 1.15 | 1.00 | 122 (lever), 152 (pedal) |
| 20 | G | 1.20 | 1.05 | 122 (lever), 152 (pedal) |
| 21 | F | 1.25 | 1.10 | 122 (lever), 152 (pedal) |
| 4th Octave | ||||
| 22 | E | 1.30 | 1.15 | 122 |
| 23 | D | 1.35 | 1.20 | 122 |
| 24 | C | 1.45 | 1.25 | 122 |
| 25 | B | 1.55 | 1.30 | 122 |
| 26 | A | 1.60 | 1.36 | 122 |
| 27 | G | 1.70 | 1.44 | 122 |
| 28 | F | 1.80 | 1.52 | 122 |
| 5th Octave | ||||
| 29 | E | 1.85 | 1.60 | 152 |
| 30 | D | 1.96 | 1.70 | 152 |
| 31 | C | 2.08 | 1.80 | 152 |
| 32 | B | 2.18 | 1.90 | 152 |
| 33 | A | 2.29 | 2.00 | 152 |
| 34 | G | 2.35 | 2.10 | 152 |
| 35 | F | 2.50 | 2.20 | 152 |
Pedal Harp Bass Wire Diameters and Lengths
| String number | Pitch | Diameter (mm) | Length (cm) |
| 5th Octave | |||
| 33 | A | 1.60 | 145 |
| 34 | G | 1.65 | 150 |
| 35 | F | 1.70 | 150 |
| 6th Octave | |||
| 36 | E | 1.80 | 155 |
| 37 | D | 1.90 | 160 |
| 38 | C | 2.00 | 165 |
| 39 | B | 2.10 | 165 |
| 40 | A | 2.25 | 170 |
| 41 | G | 2.45 | 175 |
| 42 | F | 2.50 | 180 |
| 7th Octave | |||
| 43 | E | 2.70 | 180 |
| 44 | D | 2.80 | 185 |
| 45 | C | 2.85 | 185 |
Lever Harp Bass Wire Diameters and Lengths
| String number | Pitch | Diameter (mm) | Length (cm) |
| 5th Octave | |||
| 29 | E | 1.25 | 110 |
| 30 | D | 1.29 | 110 |
| 31 | C | 1.35 | 120 |
| 32 | B | 1.44 | 120 |
| 33 | A | 1.47 | 125 |
| 34 | G | 1.50 | 135 |
| 35 | F | 1.55 | 140 |
| 6th Octave | |||
| 36 | E | 1.60 | 145 |
| 37 | D | 1.67 | 150 |
| 38 | C | 1.76 | 155 |
| 39 | B | 1.87 | 155 |
| 40 | A | 1.97 | 155 |