To calculate fret spacing for any instrument just enter the scale length, also known as the vibrating length. For most fretted instruments this is the distance between the nut and the bridge.
The results of the calculation are in the same units entered. If you enter centimetres, the results are also in centimetres.
Remember that frets spaced closer than about a quarter inch apart will be difficult to finger.
The most accurate way to lay out your scale is making all measurements from the nut using the "fret to fret" distance only to confirm your layout. Laying out frets only by measuring fret to fret will compound error. For example, if you're laying out frets by marking with a scribe and your accuracy is plus or minus 2 millimeters, you could be off by as much as 24 millimeters at the 12th fret.
Measurements are given from the end of the fingerboard (face of the nut) to the center of a fret slot.
|Ukulele||Number of Frets||Scale|
|Soprano||12||13″ to 14″|
|Concert||18||14″ to 15″|
|Tenor||18||16″ to 18″|
|Baritone||19||20″ to 24″|