Frequency of A0 (Lowest Piano A)
A0 has a frequency of 27.5 Hz — the lowest A on a standard 88-key piano.
How to use this tool
- Enter note and octave in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your frequency and the full breakdown beneath it.
A0 at 27.5 Hz is the lowest A on a standard piano keyboard.
Frequently asked questions
- What frequency is middle C?
- Middle C (C4) is approximately 261.63 Hz in standard A4=440 tuning.
- What is A4 in Hz?
- A4 is 440 Hz by international standard (ISO 16:1975).