Cigar box guitar fret calculator
Most cigar box guitars are built on a 24″ to 26″ scale, the range C. B. Gitty's string sets are made for, and 25″ is the usual choice. This calculator opens on 25″ (635 mm) with 18 frets, a starting value you change to your neck's count; the table lists each fret from the nut, in inches or millimeters.
Cigar box guitar fret positions, 25″ (635 mm) scale
Equal temperament, measured from the nut. Type your fret count to extend the table.
| Fret | From nut (mm) | From previous (mm) | To saddle (mm) |
|---|---|---|---|
| 1 | 35.64 | 35.64 | 599.36 |
| 2 | 69.28 | 33.64 | 565.72 |
| 3 | 101.03 | 31.75 | 533.97 |
| 4 | 131.00 | 29.97 | 504.00 |
| 5 | 159.29 | 28.29 | 475.71 |
| 6 | 185.99 | 26.70 | 449.01 |
| 7 | 211.19 | 25.20 | 423.81 |
| 8 | 234.98 | 23.79 | 400.02 |
| 9 | 257.43 | 22.45 | 377.57 |
| 10 | 278.62 | 21.19 | 356.38 |
| 11 | 298.62 | 20.00 | 336.38 |
| 12 | 317.50 | 18.88 | 317.50 |
| 13 | 335.32 | 17.82 | 299.68 |
| 14 | 352.14 | 16.82 | 282.86 |
| 15 | 368.02 | 15.88 | 266.98 |
| 16 | 383.00 | 14.98 | 252.00 |
| 17 | 397.14 | 14.14 | 237.86 |
| 18 | 410.49 | 13.35 | 224.51 |
How to use it
- Keep the Cigar box 25″ preset or type your own scale, nut to bridge. Switch between inches and mm beside the field.
- The number of frets starts at 18; change it to match your neck. A slide-only fretless neck still benefits: print the template and draw the fret lines as position markers.
- Pick the string type under saddle compensation to see how far back the bridge usually sits.
- Tap Print template, print at 100% (no "fit to page") and measure the 100 mm bar before you mark the wood.
Help and explanations
On 25″ the 1st fret sits 1.403″ (35.64 mm) from the nut, the 3rd at 3.978″, the 5th at 6.271″, the 7th at 8.315″ and the 12th at exactly half the scale, 12.500″ (317.50 mm). The template prints at full size on Letter or A4, with a 100 mm bar to check the printout before you saw.
The fret formula
A cigar box guitar uses the same equal-tempered fret spacing as any guitar: the distance from the nut to fret n is d = L − L ÷ 2^(n/12). The numbers agree with R. M. Mottola's table and the StewMac calculator. The number of strings doesn't change the frets, so the same template works for a 3-string GDG, a 4-string GDGB or a one-string diddley bow at the same scale.
The old rule of 18, still passed around in some build guides, divides the remaining length by 18 instead of 17.817 and leaves the upper frets flat. Use the formula, or this table, and mark every fret from the nut.
Choosing the scale length
C. B. Gitty warns that scales far from 24″ to 26″ leave their strings too slack or too tight. Within that range, 24″ (609.6 mm) puts the 12th fret at 12.000″ and feels slinkier for slide; 25.5″ (647.7 mm) moves it to 12.750″ and gives a firmer, louder string. Measure the scale from the front edge of the nut to the middle of the bridge.
Many builders cut the neck first and set the bridge last. That works if you mark the frets from the nut and place the bridge at the full scale plus a little compensation: about 1/8″ (3 mm) is a good starting point for wound strings.
Tips
- Picked the scale? See what your strings will pull in the cigar box guitar string tension calculator.
- With the box strung up, play the 12th fret against the open string with the intonation checker and move the bridge until they agree.
- Fret wire with a tang needs a slot about 0.023″ (0.58 mm) wide; a typical fret saw cuts that, a hacksaw is too wide.
Frequently asked questions
What is the best scale length for a cigar box guitar?
25″ (635 mm) is the most common, and C. B. Gitty sells its sets for 24″ to 26″. Shorter is easier for slide and small hands; longer gives more tension and volume.
What is the fret spacing on a 25-inch cigar box guitar?
From the nut: 1st fret 1.403″, 3rd 3.978″, 5th 6.271″, 7th 8.315″, 12th 12.500″, 15th 14.489″ and 19th 16.657″.
Is there a free cigar box guitar fret template PDF?
Yes: set the scale and fret count here, tap Print template and choose "Save as PDF" in the print dialog. Keep the scale at 100% and check the 100 mm bar.
How many frets should a cigar box guitar have?
There's no fixed number; it depends on how far up the neck you can reach over the box. The calculator starts at 18; change the count and the table and template follow.
Where does the bridge go on a cigar box guitar?
At the full scale from the nut, plus a little compensation: for 25″, start about 25⅛″ (638 mm) from the nut and fine-tune with the 12th-fret octave.