Bajo quinto fret calculator
A bajo quinto carries five courses of steel strings, ten strings in all, on a long guitar-size neck. The calculator opens with a 648 mm scale and 19 frets, the figures of the Fortaleza F1 bajo quinto as listed by Musician's Friend (25-1/2″ scale, 19 frets). On that scale the 1st fret sits 36.37 mm (1.432″) from the nut and the 12th lands at 324.00 mm (12.756″), exactly half the scale.
Bajo quinto fret positions, 648 mm scale
Equal temperament, 19 frets, distances measured from the nut.
| 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 |
| 17 | 405.27 | 14.43 | 242.73 |
| 18 | 418.90 | 13.62 | 229.10 |
| 19 | 431.76 | 12.86 | 216.24 |
Musician's Friend, Fortaleza F1 Silver Bajo Quinto (25-1/2″ scale, 19 frets)
How to use it
- The Bajo quinto 648 mm preset is already selected. To match a different instrument, measure from the nut to the 12th fret, double it and type that as the scale.
- Set the number of frets: 19 on the Fortaleza F1; count the frets on yours if you are copying an old neck.
- Leave Saddle compensation on bass: the bajo quinto is strung with heavy wound strings, so it needs more setback than a guitar.
- Choose Letter or A4, tap Print template, keep the scale at 100% and measure the 100 mm bar before you cut.
Help and explanations
Change the scale or the fret count if your neck is different, read the table in mm or inches and print the template at 100% to mark the slots. Everything runs in the browser, free.
Scale length and frets on a bajo quinto
Bajo quintos and bajo sextos commonly sit on a 25.5″ (647.7 mm) scale, the same length as a Fender-style guitar: the Fortaleza F1 bajo quinto and the Lucida LG-BS1-E bajo sexto both list it. What changes is the fret count and the string load. The Fortaleza has 19 frets, and its 19th fret falls 431.76 mm (17.00″) from the nut; the Lucida bajo sexto has 16.
The fret math does not care about string count or courses. Each fret sits at d = L − L ÷ 2^(n/12), the equal-temperament formula used by R. M. Mottola and the StewMac calculator, so a 648 mm bajo quinto gives 162.55 mm to the 5th fret and 215.51 mm to the 7th.
Saddle compensation with octave courses
Every string on a bajo quinto is wound, from the .026 on the first course to the .078 low A in D'Addario's EJ85 set. Heavy wound strings go sharp when fretted, so the calculator suggests the bass range, 3 to 6 mm past the nominal scale, as a starting estimate. The 4th and 5th courses pair a thin octave string with a thick one, and the two never intonate exactly alike: set the saddle for the thick string, which is the one you hear as the bass line, and check the octave string afterwards.
Finish with the intonation checker: the 12th-fret note has to sound one octave above the open course.
Tips
- Mark every slot from the nut, never by adding fret-to-fret spacings: on 19 frets the ruler errors add up.
- Measure the printed 100 mm bar. If it reads 98 or 102 mm, the printer rescaled the page.
- Once it is strung, tune the five courses with the bajo quinto tuner.
Frequently asked questions
What is the scale length of a bajo quinto?
25.5″ (647.7 mm) on the Fortaleza F1, the same as most bajo sextos. The calculator rounds it to 648 mm; the difference at the 12th fret is 0.15 mm.
Where is the 12th fret on a bajo quinto?
At half the scale: 324.00 mm (12.756″) from the nut on 648 mm, or 12.750″ on an exact 25.5″ scale.
How many frets does a bajo quinto have?
The Fortaleza F1 has 19. The 19th fret sits 431.76 mm (17.00″) from the nut. Older and handmade instruments vary, so count yours.
Is the bajo quinto fretboard the same as a bajo sexto?
The scale is the same, 25.5″, so the frets fall in the same places. The bajo sexto adds a sixth course (low E) and makes the neck wider; fret counts differ by model, 16 on the Lucida LG-BS1-E.
How much saddle compensation does a bajo quinto need?
Start with the bass range, 3 to 6 mm past the scale, more on the low A course. It is an estimate: the final setting comes from the octave at the 12th fret.