A3 at every common reference pitch
A note’s frequency depends on what A4 is tuned to. The standard is 440 Hz; the other three are the ones you are most likely to meet. The cents column is how far each one sits from the 440 version — the same for every note, because changing the reference moves the whole scale together.
| Reference | A3 | vs 440 |
|---|---|---|
| A4 = 415 Hz · Baroque pitch | 207.50 Hz | −101.3¢ |
| A4 = 432 Hz · “Verdi” pitch | 216.00 Hz | −31.8¢ |
| A4 = 440 Hz · Standard (ISO 16) | 220.00 Hz | — |
| A4 = 442 Hz · Orchestral | 221.00 Hz | +7.9¢ |
One cycle of A3 lasts 4.545 ms, and its wavelength in air at 20 °C is 1.56 m. Hold it as a steady tone in the tone generator.
A3 on the piano
A3 is key 37 of 88, counting from the bottom — a white key. Press any key below to compare it with its neighbours.
A3 on the guitar
In standard tuning A3 is played in 4 places: 6th (low E) string, fret 17, 5th (A) string, fret 12, 4th (D) string, fret 7 and 3rd (G) string, fret 2. The same pitch in each place, with a different tone: lower strings sound warmer. Guitar music is written an octave higher than it sounds, so on a guitar part this note is printed as A4.
A3 on the staff
Instruments that can play A3
42 instruments play A3 within the normal range, and 2 reach it only at the extreme of theirs. Each links to its range chart; for a transposing instrument, the note on its part is shown.
Guitars and basses
Plucked and struck strings
Woodwind
Brass
Only at the extreme of their range
Voices: A3 is inside the typical range of the bass, baritone, tenor, alto and mezzo-soprano. Test your own range.
The harmonics of A3
A played A3 is not one frequency. A string or a pipe also sounds whole-number multiples of it, and the mix of those harmonics is the instrument’s tone. Here is where the first eight land — and why the 7th sounds out of tune against a piano.
| Harmonic | Frequency | Nearest note | Off by |
|---|---|---|---|
| 1 (fundamental) | 220.00 Hz | A3 | 0¢ |
| 2 | 440.00 Hz | A4 | 0¢ |
| 3 | 660.00 Hz | E5 | +2.0¢ |
| 4 | 880.00 Hz | A5 | 0¢ |
| 5 | 1100.0 Hz | C♯6 | −13.7¢ |
| 6 | 1320.0 Hz | E6 | +2.0¢ |
| 7 | 1540.0 Hz | G6 | −31.2¢ |
| 8 | 1760.0 Hz | A6 | 0¢ |
Frequently asked questions
What is the frequency of A3?
A3 is 220.00 Hz in equal temperament with A4 tuned to 440 Hz, the international standard. At A4 = 432 Hz it is 216.00 Hz, and at the orchestral A4 = 442 Hz it is 221.00 Hz.
Which octave is A3 in?
The number is the octave in scientific pitch notation, where each octave starts on C and C4 is middle C. A3 is in octave 3, 3 semitones below middle C. In Helmholtz notation, used in older books, it is written a.
How do I play A3 on a piano?
A3 is key 37 of 88, counting from the bottom — a white key.
Which instruments can play A3?
42 of the instruments we chart play A3 within their normal range, including violin, viola, cello, guitar, 7-string guitar, and 2 more reach it only at the extreme of their range.
Typing it? A3 is also written A3. Convert any frequency on the Hz-to-note converter.