String Spacing Calculator

Most guitars have strings spaced so that the gap between each string is the same. Since each string has a different gauge (thickness), this means that the center of the strings are not equidistant.

This calculation applies along the full length of the strings, from the nut to the bridge. It is typically used for calculating the position of the nut slots, but can also be used for slotting a bridge if needed.

To calculate the position of each nut slot, we need to take into account:

• $W$ = width of the nut (edge to edge) - in mm
• $D_E$ = distance from the edge of the E string to the edge of the nut on the bass side (in mm)
• $D_e$ = distance from the edge of the e string to the edge of the nut on the treble side (in mm)
• $N$ = the number of strings
• $G$ = the gauge of all the strings combined. We typically measure this in thousands of an inch, since that's the unit used by most string manufacturers, but for the calculation we'll convert it to millimeters. For example if my gauges are 9, 11, 16, 26, 36, 46, $G$ would be the sum which is 0.154", or 3.91mm.

Based on this, we can calculate what the distance between each string $D$ should be so that it is the same between each string. It will be equal to the width of the nut $W$ minus the space taken by the strings $G$ minus the space on each side of the nut $D_E + D_e$, divided by the number of gaps between strings which is $N-1$.

If we use the formula with the following parameters that are pretty standard for an electric guitar:

• $W = 44$ mm
• $D_E = 3$ mm
• $D_e = 3$ mm
• $N = 6$ strings
• $G = 3.91$ mm (0.154", sum of 9, 11, 16, 26, 36, 46 gauges)

then we get:

The edge of each string will be 6.818mm apart from each other.