FAQ

What does the cents reading mean?

A cent is one hundredth of a semitone. The gauge shows how far your frequency sits from the nearest in-tune note: within ±5 cents it reads in tune, beyond that it says sharp or flat. It is the standard unit for fine tuning.

What temperament does PitchSense use?

Twelve-tone equal temperament, using the formula shown at the bottom of the page: f(n) = A4 · 2^((n − 69) / 12), where n is the MIDI number. Just intonation and historical temperaments are not offered.

Why can I change A4?

A4 is the concert-pitch reference the whole scale is built from. 440 Hz is the modern standard, but orchestras and producers use everything from 432 to 444 Hz. Changing it re-derives every note, harmonic and table value.

Which A4 values are available?

432, 434, 436, 438, 440, 442 and 444 Hz. Values outside that set, such as 415 Hz for baroque pitch, are not offered.

How accurate are the conversions?

They use the equal-temperament formula at full floating-point precision. The converter shows frequencies to two decimals and the reference table to four.

Does the tuner need a microphone?

Yes. It listens through the device microphone after you allow access, and it detects one clear pitch at a time between 20 Hz and 4 kHz. It is a microphone tuner, so accuracy depends on the microphone and the room. See Tune from the microphone.

What does the harmonic series show?

The first eight partials of the fundamental you type — ×1 to ×8 — each with its frequency, nearest note and cents deviation. It explains why an overtone lands slightly off a piano note.

What does the tool remember?

Only the A4 reference, the wave shape and the volume. They are stored on the device and, when you are signed in, synced to your account. The frequency, note and harmonic you typed are not stored — they live in the page URL instead, see Share or bookmark a readout.

Can I search the table by flats?

Yes. The search matches sharps and flats in either spelling: C#4, Db4, F♯ and Eb all work, as do MIDI numbers and the start of a frequency.

Is it free?

Yes. PitchSense is one of the free tools on Squaresmile Tools. It opens with a free account — no card, no subscription.