A4 = 415 Hz
A common modern approximation for Baroque pitch, one equal-tempered semitone below 440 Hz.
Concert Pitch Calculator
Choose an A4 reference, calculate exact note frequencies, and see how far it sits above or below standard 440 Hz.
Selected note frequency
440.00 Hz
At A4 = 440 Hz
440.00 Hz
Shift from standard pitch
+0.0 cents
What concert pitch changes
Concert pitch is the reference frequency an ensemble assigns to A4, the A above middle C. Moving A4 changes every note by the same musical interval. It does not change note names, fingerings, or the intervals between notes.
A chromatic tuner must use the same reference as the people or instruments you are playing with. If an orchestra tunes to 442 Hz while your tuner remains at 440 Hz, your instrument will read roughly 7.9 cents sharp even when it matches the orchestra.
A4 = 432 Hz
An alternative reference used by some individual musicians. It is about 31.8 cents below 440 Hz.
A4 = 440 Hz
The standard reference for most modern instruments, tuners, educational material, and ensembles.
A4 = 442–443 Hz
Used by some orchestras for a slightly higher ensemble pitch. Always follow the reference supplied by the ensemble.
How the calculation works
In 12-tone equal temperament, adjacent notes are separated by a factor of 2 raised to one twelfth. For MIDI note number n, the frequency is A4 × 2(n − 69) / 12. The calculator applies that formula to your selected A4 reference.
Use the same reference live
Set the A4 control on the online tuner to the same value, then play one sustained note at a time in a quiet room.
Open the chromatic tuner