Free interactive tool
Tone Generator (Hz to Note)
Slide a frequency, see the wave compress, and hear the nearest musical note name itself.
See the shape of a pitch
Slide the frequency and watch the wave compress; the nearest musical note names itself.
Pitch is not mystical — it is how many times per second the wave repeats, and one octave up is exactly twice the frequency.
- Find A at 440 Hz, then find the A one octave above it.
- Press Play at 220 Hz and 440 Hz and listen for the octave.
- Count the cycles in the window at 110 Hz versus 880 Hz.
Pitch is repetition speed: A4 is 440 vibrations per second, and one octave up is exactly double. The waveform window shows the cycles compressing as frequency rises, with the nearest note and its cents offset labeled live.
Use it to find a starting pitch, train octave recognition, or check roughly how sharp or flat a tone sits.
What frequency is middle A?
A4 = 440 Hz in modern concert pitch; the A an octave below is 220 Hz.
What is a cent?
A hundredth of a semitone. Most listeners notice pitch differences somewhere above 5–10 cents.