Musical Note to Frequency Calculator
Fill in the values and the answer updates as you type.
How the Musical Note to Frequency Calculator works
MIDI number = 12 × (octave + 1) + semitones above C. Frequency = A4 × 2^((MIDI − 69) ÷ 12), so every semitone multiplies the pitch by about 1.0595 and every octave doubles it. Middle C is C4 (MIDI 60), and valid MIDI notes run from C-1 to G9. Some baroque ensembles tune A4 to 415 Hz, and some orchestras use 442 Hz, so the reference pitch is adjustable. Example: with Note A, Octave 4, and Reference pitch (A4) 440 Hz, the result is Frequency (Hz) = 440; MIDI note number = 69; Period (ms) = 2.2727.
Inputs and results
The Musical Note to Frequency Calculator takes 3 inputs and gives 4 results.
What you enter
- Note — starts at A. Choose from: C, C#, D, D#, E and F and more.
- Octave — starts at 4.
- Reference pitch (A4) (Hz) — starts at 440.
What you get
- Frequency (Hz)
- MIDI note number
- Period (ms)
- One octave higher (Hz)
Example: Musical Note to Frequency Calculator with the starting values
With note A, octave 4 and reference pitch (a4) 440 Hz, the calculator returns:
| Frequency (Hz) | 440 |
|---|---|
| MIDI note number | 69 |
| Period (ms) | 2.2727 |
| One octave higher (Hz) | 880 |
Change any value above and the results update straight away.
Musical Note to Frequency Calculator FAQ
How do I use the Musical Note to Frequency Calculator?
Enter note, octave and reference pitch (a4) in the fields, then read frequency (hz), midi note number, period (ms) and one octave higher (hz) in the result panel. The answer updates as you type, and you can press Calculate or Enter to refresh it. Use “Copy link” to share your exact numbers with someone else.
What does the Musical Note to Frequency Calculator calculate?
Frequency in Hz, MIDI number, and period for any note. It returns frequency (hz), midi note number, period (ms) and one octave higher (hz) from the 3 values you provide.
What values does the Musical Note to Frequency Calculator start with?
It opens with note A, octave 4 and reference pitch (a4) 440 Hz so you can see a working result straight away. Replace them with your own numbers, or press Reset to return to these starting values.
Is the Musical Note to Frequency Calculator free and private?
Yes. It is free, needs no account, and runs in your browser, so nothing you type is sent to or stored on our servers. See the Privacy Policy for details.
Can I rely on the Musical Note to Frequency Calculator for important decisions?
Treat the result as a well-rounded estimate. Real situations often have details a general calculator cannot know, so confirm important decisions with a qualified professional. See the Disclaimer for more.