Convert any note’s frequency between A4 tuning standards, like the modern standard of 440Hz and the alternate 432Hz reference some musicians prefer.
“A4” refers to the frequency assigned to the A note above middle C, the reference point every other note is tuned relative to. Most modern instruments and tuners use 440Hz, but some musicians and ensembles tune to 432Hz or other reference points instead.
A4 Reference Converter
Note (e.g. A4, C4, E5):
Source A4 Standard (Hz):
Target A4 Standard (Hz):
Frequency at Source Standard: —
Frequency at Target Standard: —
Difference: —
Why Tuning Standards Differ
440Hz became the widely adopted international standard for A4 in the 20th century, and it’s what most tuners, pianos, and orchestras use today. Some musicians tune to 432Hz instead, citing historical tuning practices or a preference for how it sounds, though this remains a minority practice. Recording with or matching a track tuned to a different standard requires knowing the exact frequency shift involved.
How to Use This Calculator
- Note: enter the note and octave you want the frequency for, like A4 or E5.
- Source A4 Standard: the tuning reference the note is currently based on (440 by default).
- Target A4 Standard: the tuning reference you want to convert to (432 by default).
- Click Convert to see both frequencies and the difference in cents.
Example: A4 at the 440Hz standard is 440.00Hz; the same note at the 432Hz standard is 432.00Hz, a difference of about 31.77 cents.
The Formulas and More Examples
A note’s frequency depends on its distance in semitones (n) from A4: f = A4 × 2^(n ÷ 12). Changing the reference from 440 to 432 Hz scales every frequency by 432 ÷ 440, and the shift in cents is 1200 × log₂(432 ÷ 440) ≈ −31.77.
More examples: Middle C (C4) is about 261.63 Hz at A4 = 440 and about 256.87 Hz at A4 = 432. E5 is about 659.26 Hz at 440 and about 647.27 Hz at 432.
When You Need This Conversion
This helps when you play along with a track tuned to a different reference, retune a digital keyboard or software instrument, or prepare a recording to match an ensemble that tunes to 442 Hz or 415 Hz for baroque music. Knowing the difference in cents tells you whether a pitch-shift or a retune is enough.
Did You Know?
- Before 440Hz was standardized, orchestral tuning pitches varied widely across Europe, sometimes differing by a full semitone or more between cities and eras.
- A cent is 1/100th of a semitone, the standard unit musicians use to describe very small pitch differences that are too subtle to call a full note.
Frequently Asked Questions
Does the shift in cents change depending on the note?
No, shifting the A4 reference moves every note by the same number of cents, since it’s a uniform change to the whole tuning system, not just one note.
Can I use this for any note format?
Enter a letter (A through G), an optional sharp (#), and an octave number, such as C4 or F#3.
Is 432 Hz better than 440 Hz?
Which sounds better is a matter of taste. Claims that 432 Hz has special health effects are not supported by good scientific evidence. Both are valid tuning standards, and this tool simply shows the exact difference.
How do I retune to a different A4 in practice?
Set your tuner’s calibration to the new reference, such as 432 or 442, and tune as usual. Fixed-pitch instruments such as pianos need a technician to retune.