Frequency to Note Calculator
Closest Note
A4
Cents Offset
0 cents
Exact Note Frequency
440.00 Hz
Wavelength in Air
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How Frequency Relates to Musical Notes
In equal temperament, each semitone is separated by 2^(1/12) ≈ 1.0595. Standard reference: A4 = 440 Hz. Any note: f = 440 x 2^(n/12).
Cents measure fine pitch differences: 100 cents = 1 semitone. +10 cents means slightly sharp; -10 means flat. Tuners aim for within 3 cents.
Wavelength in air (343 m/s) = 343/frequency. A2 (110 Hz) has a wavelength of about 3.1 meters.
Frequently Asked Questions
Why is A4 = 440 Hz?
Internationally standardized in 1955. Before that, concert pitch varied from 415-466 Hz. Some orchestras use 442-443 Hz.
What is equal temperament?
Divides the octave into 12 equal semitones. Allows playing in any key with consistent intervals.
What are cents?
Logarithmic unit: 100 cents = 1 semitone, 1200 cents = 1 octave. Precise way to measure small pitch differences.
Range of human hearing?
Roughly 20 Hz to 20,000 Hz. A piano covers A0 (27.5 Hz) to C8 (4186 Hz).