Note Frequency Calculator – Find the Hz Frequency of Any Musical Note

Find the exact frequency of any musical note with our Note Frequency Calculator. Enter a note name and octave to instantly get its frequency in Hz — perfect for musicians, audio engineers, and instrument tuners.

Note

Octave

Reference Frequency (A4)

Standard: 440 Hz, Alternative: 432 Hz

Quick Select:

Frequency Results

Select a note and click Calculate to see frequency

Understanding Note Frequencies

Equal temperament: Each semitone is 2^(1/12) ≈ 1.0595× the previous frequency
A4 = 440 Hz: International standard since 1955
Octave relationship: Each octave doubles the frequency (A4 = 440 Hz, A5 = 880 Hz)
MIDI notes: A4 = MIDI note 69, each semitone ±1
Wavelength: λ = v/f where v ≈ 343 m/s (speed of sound)

Note: Some orchestras tune to 442 Hz or 444 Hz for a brighter sound. Historical pitch varied widely (A = 415 Hz in Baroque era).

How to Calculate Note Frequency

Select Your Note

Choose the note name (C, D, E, etc.) and octave number from the dropdown menus.

Set Reference Pitch

Use standard A4=440Hz or adjust for alternative tunings like 432Hz.

Get Instant Results

View the exact frequency in Hz, wavelength, MIDI number, and nearby notes.

Key Features of This Note Frequency Calculator

✓Equal Temperament Formula

Uses the standard f = A4 × 2^(n/12) formula for accurate frequency calculations across all octaves.

✓Custom Reference Frequency

Adjust the A4 reference from standard 440Hz to 432Hz, 442Hz, or any custom tuning.

✓MIDI Note Numbers

Get the corresponding MIDI note number for digital audio workstation integration.

✓Wavelength Calculation

See the sound wavelength in meters based on the speed of sound at room temperature.

✓Nearby Notes Reference

View adjacent semitones with their frequencies and cent differences for tuning context.

Frequently Asked Questions About Note Frequencies

What is the frequency of middle C?

Middle C (C4) has a frequency of approximately 261.63 Hz when A4 is tuned to 440 Hz. This is the C closest to the middle of a piano keyboard.

Why is A4 set to 440 Hz?

A4=440Hz became the international standard in 1955 (ISO 16). Before that, tuning varied widely - Baroque orchestras often used A=415Hz, while some modern orchestras prefer 442Hz for a brighter sound.

How do you calculate frequency from note name?

Use the formula f = 440 × 2^(n/12), where n is the number of semitones from A4. For example, C5 is 9 semitones above A4, so f = 440 × 2^(9/12) ≈ 523.25 Hz.

What is 432 Hz tuning?

432 Hz tuning sets A4 to 432 Hz instead of 440 Hz. Proponents claim it sounds more natural, though this is debated. All other notes shift proportionally - C4 becomes about 256 Hz instead of 261.63 Hz.

How does octave affect frequency?

Each octave doubles the frequency. A4 is 440 Hz, A5 is 880 Hz, and A3 is 220 Hz. This 2:1 ratio is why notes an octave apart sound so similar - they share the same harmonic series.

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