Note Frequency
Calculator
Results
- Note frequency (Hz)
- 523.25113
- Period (ms)
- 1.911128
- Wavelength (m)
- 0.655516
Music and audio results
| Note frequency (Hz) | 523.25113 |
| Period (ms) | 1.911128 |
| Wavelength (m) | 0.655516 |
formula-map diagram
- Note frequency (Hz)
- 523.25113
- Period (ms)
- 1.911128
- Wavelength (m)
- 0.655516
Musical and acoustic relationship
Formula
f = f₀ × 2^(n ÷ 12)= 523.2511306012
Note
This result is a simplified model: it applies the displayed standard formula to the values you entered, assuming twelve-tone equal temperament, a speed of sound of 343 m/s in dry air at 20 °C, an ideal free field with no reflections or air absorption, purely resistive speaker loads and Sabine's diffuse-field assumption. Real rooms, instruments, codecs and amplifiers depart from these idealisations, so measure with proper instruments for critical work.
More in Music and audio
See all →Frequently asked questions
How is a note's frequency calculated from A4?+
The calculator uses the equal-temperament formula f = 440 x 2^(n/12), where n is the number of semitones away from A4 (440 Hz) and 440 Hz is the standard concert pitch. Each semitone step multiplies the frequency by the twelfth root of two, so every octave exactly doubles the frequency.
Why does changing the reference pitch (e.g. 442 Hz) shift every note?+
The reference pitch anchors the whole scale, so raising A4 from 440 Hz to 442 Hz scales every other note's frequency by the same 442/440 ratio. Orchestras sometimes tune to 442 Hz or higher for a brighter sound, which is why the field is adjustable.
Why do octaves double or halve in frequency?+
An octave is defined as a 2:1 frequency ratio, so A5 is 880 Hz and A3 is 220 Hz, both anchored to A4 at 440 Hz. This doubling relationship is what the ear perceives as 'the same note, higher or lower.'
Does this match the notes on a piano keyboard exactly?+
Yes, standard pianos are tuned to equal temperament, so the calculator's output matches piano key frequencies when A4 is set to 440 Hz. Instruments using other tuning systems, like just intonation, will differ slightly from these values.
Why might a tuner show a slightly different frequency than the calculator?+
Real instruments drift from ideal pitch due to temperature, string age, or manufacturing tolerances, so a tuner reading 439.7 Hz for A4 is normal and not an error. The calculator gives the theoretical target frequency, not a measurement of an actual sound.