Note Frequency Calculator
Find a note's frequency from semitones above A4.
Find any note's pitch relative to concert A (A4 = 440 Hz).
The math behind it
frequency = A4 × 2^(semitones ÷ 12). Each octave (12 semitones) doubles the frequency.
Worked example
+3 semitones from A4 → C5 ≈ 523.25 Hz.
FAQ
Negative?
Lower notes — −12 is one octave down.