Charango fret calculator
Aquila's string chart lists the charango at a 37 cm scale, and the modern charango usually has 18 frets. The calculator opens with that: the 1st fret sits 20.77 mm from the nut, the 5th 92.81 mm, the 7th 123.05 mm, the 12th 185.00 mm and the 18th 239.19 mm.
Charango fret positions, 370 mm scale
Distance of each fret from the nut, from the previous fret and to the saddle on an 18-fret charango.
| Fret | From nut (mm) | From previous (mm) | To saddle (mm) |
|---|---|---|---|
| 1 | 20.77 | 20.77 | 349.23 |
| 2 | 40.37 | 19.60 | 329.63 |
| 3 | 58.87 | 18.50 | 311.13 |
| 4 | 76.33 | 17.46 | 293.67 |
| 5 | 92.81 | 16.48 | 277.19 |
| 6 | 108.37 | 15.56 | 261.63 |
| 7 | 123.05 | 14.68 | 246.95 |
| 8 | 136.91 | 13.86 | 233.09 |
| 9 | 150.00 | 13.08 | 220.00 |
| 10 | 162.34 | 12.35 | 207.66 |
| 11 | 174.00 | 11.65 | 196.00 |
| 12 | 185.00 | 11.00 | 185.00 |
| 13 | 195.38 | 10.38 | 174.62 |
| 14 | 205.18 | 9.80 | 164.82 |
| 15 | 214.43 | 9.25 | 155.57 |
| 16 | 223.17 | 8.73 | 146.83 |
| 17 | 231.41 | 8.24 | 138.59 |
| 18 | 239.19 | 7.78 | 130.81 |
Aquila Corde, South American instrument strings (charango 37 cm)
How to use it
- Tap Charango 370 mm or type your scale: measure from the nut to the 12th fret and double it.
- Set the number of frets. Modern charangos have 18; older and folk instruments may have far fewer.
- Keep the Ukulele compensation, the closest match for short nylon strings.
- Print at 100%, measure the 100 mm bar and tape the sheets on the splice line.
Help and explanations
Real charangos range from about 350 to 384 mm, so measure yours and type the scale in. The template prints at full size on Letter or A4, with a 100 mm check bar. Everything runs in your browser, free, with no sign-up.
Charango scale length and frets
Published scales cluster around 35 to 38 cm. Aquila's chart uses 37 cm and its Nylgut charango set is meant for 35 to 36.5 cm, not above 36.8 cm, while Thomann's Charango Soprano Standard measures 384 mm with 18 frets. Wikipedia gives a typical scale of about 37 cm and anything from 5 to 18 frets.
That spread matters: on a 384 mm scale the 12th fret moves to 192.00 mm, 7 mm further than on a 370 mm charango. Measure the instrument in front of you and use that number.
Short scale, small compensation
On a scale this short, every millimeter counts. The charango uses nylon or Nylgut strings at fairly low tension, and the calculator suggests 1 to 2 mm of saddle compensation, labeled as an estimate. The third course is an octave pair, E4 and E5, and the two strings may want slightly different saddle positions.
Once strung, check the octave at the 12th fret on each string with the intonation checker; the 12th fret must land at exactly half the scale.
Tips
- Mark every slot from the nut, not fret to fret: at this scale a half-millimeter error is already audible.
- Check the printed 100 mm bar before you cut. A 2 % rescale moves the 18th fret by almost 5 mm.
- Tune the five courses with the charango tuner before you check intonation.
Frequently asked questions
What is the scale length of a charango?
About 37 cm (14.6″) is typical, according to Aquila's chart and Wikipedia, with instruments from roughly 350 to 384 mm. Measure yours from the nut to the 12th fret and double it.
How many frets does a charango have?
Modern charangos usually have 18 frets. Traditional instruments can have as few as 5, according to Wikipedia.
Where is the 12th fret on a 370 mm charango?
At 185.00 mm (7.283″) from the nut. The 1st fret is at 20.77 mm, the 5th at 92.81 mm, the 7th at 123.05 mm and the 18th at 239.19 mm.
Can I use this for a ronroco or a walaycho?
Yes. The fret formula only depends on the scale length: type in the length of your instrument, for example about 420 mm for an Argentine ronroco.