Samplers, synthesizers and tuners describe pitch as a note name, a MIDI number or a frequency. The converter translates between the three in every direction, shows how far a frequency lies from the nearest note in cents and lists the period and the samples per cycle, for example for tuning a kick drum or setting a filter to a note.
Each of the three fields updates the other two. Note names use English spelling with # and b; H is accepted as B.
| Note | MIDI | Frequency (Hz) | Period (ms) | Samples per cycle |
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The highlighted row is the current note. All values follow equal temperament at the chosen reference pitch and sample rate.
Frequency = reference × 2^((MIDI number − 69) ÷ 12). MIDI number 69 is A4, which is usually set to 440 Hz; each semitone multiplies the frequency by the twelfth root of two.
MIDI number = 69 + 12 × log₂(frequency ÷ reference). The distance to the nearest whole number times 100 is the deviation in cents; a semitone has 100 cents.
Period in milliseconds = 1000 ÷ frequency, samples per cycle = sample rate ÷ frequency. FL Studio names MIDI number 60 C5, one octave higher than scientific pitch notation, which calls it C4.
Everything is calculated in the browser. The converter covers equal temperament only; other tunings and microtonal scales need their own tables.