MusicReasonScales, Keys, Intervals, and Notation
What note is this frequency closest to?
Enter a frequency. This tool finds the nearest equal-tempered note and the signed cents away from it, under an explicit A4 reference, without ever calling the result "in tune."
Answer
Want to learn more? Tuning, Cents, Temperament, and Reference Pitch
Understand
"Nearest equal-tempered note" is a rounding convention, not a verdict: it tells you which note name is closest under 12-tone equal temperament, not whether the frequency itself is musically correct for any given context or temperament.
Worked examples
440 Hz gives A4, 0 cents. 880 Hz gives A5, 0 cents. 442.55 Hz gives A4, about +10 cents, since it sits slightly sharp of the 440 Hz reference for that note.
Method and limitations
The nearest MIDI note is round(69 + 12·log2(f/A4)), and signed cents are the difference between the exact and rounded MIDI value scaled to 100 cents per semitone. A tie at exactly half a semitone rounds using standard half-up policy. This is the same formula Reference Pitch and Cents uses in its frequency-to-note mode.
Why a separate, narrower tool exists
This is the single most common direction of the three modes Reference Pitch and Cents offers: someone has measured or read off a frequency and wants to know what note it is closest to. Splitting it into its own focused page means a link aimed at exactly this job lands on a page that asks for one input, not three mode choices first.