How to use the bass tuner
- Choose your bass (4, 5 or 6 string) and press Start tuner, then allow the microphone.
- Pluck the lowest string firmly and let it ring for a moment: low notes take a fraction of a second to read.
- If the needle is left of centre the string is flat: tighten the peg. Right means sharp: loosen it.
- Work up through the strings (E, A, D, G on a 4-string).
- Check each string again when you have finished.
- A 4-string bass is tuned E A D G, an octave below the lowest four strings of a guitar.
- A 5-string adds a low B (about 31 Hz); a 6-string adds a high C.
- Low notes have long wavelengths, so the tuner uses a longer listening window and needs a steady note.
Bass tuning chart
4-string standard (E A D G)
| String | Note | Frequency |
|---|---|---|
| 4th | E1 | 41.20 Hz |
| 3rd | A1 | 55.00 Hz |
| 2nd | D2 | 73.42 Hz |
| 1st | G2 | 98.00 Hz |
5-string (B E A D G)
| String | Note | Frequency |
|---|---|---|
| 5th | B0 | 30.87 Hz |
| 4th | E1 | 41.20 Hz |
| 3rd | A1 | 55.00 Hz |
| 2nd | D2 | 73.42 Hz |
| 1st | G2 | 98.00 Hz |
6-string (B E A D G C)
| String | Note | Frequency |
|---|---|---|
| 6th | B0 | 30.87 Hz |
| 5th | E1 | 41.20 Hz |
| 4th | A1 | 55.00 Hz |
| 3rd | D2 | 73.42 Hz |
| 2nd | G2 | 98.00 Hz |
| 1st | C3 | 130.81 Hz |
Drop D (D A D G)
| String | Note | Frequency |
|---|---|---|
| 4th | D1 | 36.71 Hz |
| 3rd | A1 | 55.00 Hz |
| 2nd | D2 | 73.42 Hz |
| 1st | G2 | 98.00 Hz |
Half step down (E♭ A♭ D♭ G♭)
| String | Note | Frequency |
|---|---|---|
| 4th | E♭1 | 38.89 Hz |
| 3rd | A♭1 | 51.91 Hz |
| 2nd | D♭2 | 69.30 Hz |
| 1st | G♭2 | 92.50 Hz |
Tips for an accurate reading
- Pluck one string at a time and let it ring. Muted or buzzing strings are hard to read.
- Use a quiet room. Background music or voices can confuse any tuner.
- Hold the device close to the instrument's sound hole or body.
- Tune up to the note. If you overshoot, go below the note and tighten up to it again.
- Re-check every string once you have finished, as adjusting one affects the neck tension.
How the tuner works
Every note is a vibration with a frequency: A4 is 440 vibrations per second, or 440 Hz. The tuner listens through your microphone and uses a pitch-detection method called YIN to find how often the sound repeats. It compares that frequency with the one the string should have and shows the gap in cents, where 100 cents is one semitone (the step between two neighbouring piano keys). Within 5 cents of the target the note turns green: that is far finer than most listeners can hear.
Troubleshooting
- "The microphone is blocked": open your browser's site settings, allow the microphone for this page, and reload.
- The needle jumps around: let the note ring for a second, mute the other strings and move away from noise.
- It shows the wrong octave or note: pluck more gently, and check the right tuning and instrument are chosen above.
- Nothing happens on iPhone: tap Start tuner yourself; browsers only allow the microphone after a tap.
Frequently asked questions
What is standard bass tuning?
A 4-string bass is tuned E1, A1, D2, G2, which is E A D G from the thickest string to the thinnest, with the lowest at 41.20 Hz.
Why is the bass tuner slower than the guitar tuner?
Bass notes vibrate slowly, so the tuner needs to listen for several cycles to be sure of the pitch. Let the note ring and it will settle.
Can it tune a 5-string bass?
Yes. Choose the 5-string option for B E A D G, including the low B at about 30.87 Hz.
What if the tuner cannot hear my instrument?
Allow the microphone, get closer to the sound, pluck one string clearly in a quiet room and let it ring. If it still struggles, tune by ear with the reference notes (the ▶ buttons).
More tuners and tools
Guitar tuner, Ukulele tuner, Violin tuner, Mandolin tuner, Banjo tuner, Chromatic tuner. Once you are in tune, learn the chord shapes in the guitar chord library or the ukulele chord library, find the easiest capo position with the capo calculator, or look up what any set of notes is called with the chord finder.