Bajo sexto fret calculator
The bajo sexto is the 12-string bass guitar of norteño and Tejano music, built with six double courses. The reference model here, the Lucida LG-BS1-E, has a 25.5″ (647.7 mm) scale and 16 frets, the same scale length as a Fender-style electric. The calculator opens at 648 mm and 16 frets: the 1st fret sits 36.37 mm from the nut, the 5th 162.55 mm, the 12th 324.00 mm and the 16th 390.84 mm.
Bajo sexto fret positions, 648 mm scale
Distance of each fret from the nut, from the previous fret and to the saddle on a 25.5″ bajo sexto with 16 frets.
| Fret | From nut (mm) | From previous (mm) | To saddle (mm) |
|---|---|---|---|
| 1 | 36.37 | 36.37 | 611.63 |
| 2 | 70.70 | 34.33 | 577.30 |
| 3 | 103.10 | 32.40 | 544.90 |
| 4 | 133.68 | 30.58 | 514.32 |
| 5 | 162.55 | 28.87 | 485.45 |
| 6 | 189.79 | 27.25 | 458.21 |
| 7 | 215.51 | 25.72 | 432.49 |
| 8 | 239.79 | 24.27 | 408.21 |
| 9 | 262.70 | 22.91 | 385.30 |
| 10 | 284.32 | 21.63 | 363.68 |
| 11 | 304.73 | 20.41 | 343.27 |
| 12 | 324.00 | 19.27 | 324.00 |
| 13 | 342.18 | 18.18 | 305.82 |
| 14 | 359.35 | 17.16 | 288.65 |
| 15 | 375.55 | 16.20 | 272.45 |
| 16 | 390.84 | 15.29 | 257.16 |
Chorder, Lucida LG-BS1-E Bajo Sexto (25-1/2″ scale, 16 frets)
How to use it
- The Bajo sexto 25.5″ preset loads 648 mm and 16 frets. Measure your own instrument first: nut to 12th fret, times two.
- Switch to inches if you work with a fractional ruler; every row of the table converts.
- Leave the compensation on Bass: the heavy wound strings of a bajo sexto need the saddle set further back than on a guitar.
- Print at 100%, measure the 100 mm bar and tape the sheets together on the splice line.
Help and explanations
Change the scale if your bajo measures differently, then print the full-size template on Letter or A4 to mark a new fretboard or check the slots on an old one. It runs in your browser, free, with no sign-up.
Bajo sexto scale length and frets
Bajo sextos are not standardized. Factory instruments like the Lucida use 25.5″; hand-built bajos from Texas and northern Mexico vary from builder to builder, so measure before you trust any preset. According to Wikipedia, the neck traditionally joins the body at the 12th fret, which leaves only a few frets over the body: the Lucida stops at 16.
The bajo quinto, the five-course version without the low E course, follows the same design. Because fret positions depend only on the scale length, type in the length you measured and the table is valid for either instrument.
Why compensation matters on a bajo sexto
Every string in a D'Addario EJ86 set is wound, from the .026 up to the .092 low E, and the three bass courses are octave pairs. Heavy wound strings go sharper when fretted, so a bajo sexto saddle usually sits further behind the nominal scale than a 6-string guitar's. The calculator shows a starting range for bass, 3 to 6 mm past the scale, labeled as an estimate.
The final setting comes from the octave: the note at the 12th fret must sound exactly one octave above the open string. Check each course with the intonation checker; on octave courses, test the thick and the thin string separately.
Tips
- On a 12th-fret neck joint, the 12th fret lies right at the body. On a 648 mm scale it must land at 324.00 mm, exactly half; if it doesn't, the scale isn't what you think.
- Mark every slot from the nut, never fret to fret, so small ruler errors don't add up.
- After a refret, tune the double courses one string at a time with the bajo sexto tuner.
Frequently asked questions
What is the scale length of a bajo sexto?
There is no single standard. The Lucida LG-BS1-E uses 25.5″ (647.7 mm), the same as a Fender guitar, while hand-built bajos vary. To check yours, measure from the nut to the 12th fret and double it.
How many frets does a bajo sexto have?
The Lucida LG-BS1-E has 16. Traditional bajos join the neck to the body at the 12th fret, so the frets above the 12th vary by builder.
Where is the 12th fret on a 25.5″ bajo sexto?
At 12.75″ (323.85 mm) from the nut, half the scale. The 1st fret is at 1.431″ (36.35 mm), the 5th at 6.397″ (162.47 mm) and the 7th at 8.481″ (215.41 mm).
Is a bajo sexto the same as a 12-string guitar?
No. A 12-string guitar is tuned E A D G B E with octave strings on the four lower courses. A bajo sexto is tuned in fourths, E A D G C F, about an octave lower, with octaves only on the three bass courses. The fret formula is the same for both.
Can I use this calculator for a bajo quinto?
Yes. A bajo quinto drops the low E course, but fret positions depend only on the scale length. Measure your instrument and type the length in.