Free studio tool
Note to frequency.
And back again.
Pick a note or type a frequency. The calculator names it, shows how many cents sharp or flat it is, and gives you the MIDI number, piano key, period and wavelength.
- Free, no signup
- A4 from 400–480 Hz
- Play the piano sample
- Or a pure sine
Note frequency calculator
| Harmonic | Frequency | Nearest note |
|---|
Tuning
Equal temperament, stated plainly
Each semitone is the twelfth root of two, about 1.059463. MIDI note 69 is A4. Frequency is A4 × 2(MIDI − 69) / 12. Scientific pitch notation calls middle C "C4", which is MIDI 60 and 261.63 Hz when A4 is 440.
Every piano key from A0 to C8 has its own page, starting at A0 and middle C. Those pages are the canonical note references. This calculator is the tool for arbitrary frequencies and alternate A4 tunings.
Name the note, then train to hear it.
Interval and chord drills in the app use this same equal-tempered piano.
Download on theApp Store- EQ & compressionDaily drills on drums, bass, guitars and full mixes.
- Intervals & chordsPiano training that uses the same note names as these pages.
- Studio toolsMetronome, tone generator and tap tempo live in the app too.
Explore the cluster
Keep training & testing
FAQ
Calculator questions
Which tuning does this use?
Twelve-tone equal temperament. A4 defaults to 440 Hz and you can set it anywhere from 400 to 480. Every note page on this site uses 440 unless it says otherwise.
Why does the piano sound different from the sine wave?
The piano button plays a sampled piano, pitch-shifted when the note is outside the recorded range (MIDI 60–84). The sine button is a pure oscillator at the exact frequency, which is what you want for tuning and for hearing beats.
How loud should I listen?
Keep the tone at a conversation level. These pages can generate steady tones and noise, which fatigue your ears faster than music. If anything rings or feels uncomfortable, stop and turn the volume down.