256 Hz: the “scientific pitch” middle C

Scientific (or philosophical) pitch fixes middle C at 256 Hz, a power of two, so that every C is a whole number of hertz: 128, 256, 512. It is convenient for physics and acoustics teaching and never became a musical standard.

Tuning forks of 256 Hz and 512 Hz are also the ones clinicians use for bedside hearing checks such as the Rinne and Weber tests.

Which note 256 Hz is at other reference pitches

“In tune” depends on what A4 is tuned to, so the same frequency is a slightly different distance from the nearest note in each tuning.

Octaves of 256 Hz

Doubling a frequency raises it an octave and halving lowers it one, so these all have the same note name and the same offset from it.

• 32.00 Hz · C1
• 64.00 Hz · C2
• 128.00 Hz · C3
• 512.00 Hz · C5
• 1024.0 Hz · C6
• 2048.0 Hz · C7

Harmonics of 256 Hz

A real instrument playing 256 Hz also sounds whole-number multiples of it. The first eight, and the notes they fall nearest:

Period and wavelength

One cycle of 256 Hz lasts 3.906 milliseconds; in air at 20 °C, where sound travels at about 343 metres a second, one wavelength is 1.34 metres.

Convert another frequency

Or hold 256 Hz as a steady tone, sweep from it, or beat it against a second tone in the tone generator. The note frequency chart lists every note from C0 to B8.

Frequently asked questions

Related frequencies

• 432 Hz — an alternative tuning pitch
• 440 Hz — the standard tuning pitch
• 528 Hz — a “solfeggio” frequency