Frequency to Note Converter - Hz to Musical Note | BeatKey Tools

Frequency to Note Converter

Enter any Hz frequency and instantly get the musical note name, MIDI number, and how many cents off-pitch it is.

A4
note name
69
MIDI number
exact pitch
pitch accuracy
Exact pitch for A4: 440.00 Hz

Famous Frequencies - Quick Lookup

Click any frequency to load it into the converter.

How to Convert Hz to a Musical Note

The math is based on the equal temperament tuning system where each octave doubles the frequency and there are 12 semitones per octave.

// Formula: Hz to MIDI note number
MIDI = 69 + 12 * log2(Hz / 440)
// Worked examples:
261.63 Hz: MIDI = 69 + 12 * log2(261.63/440) = 69 + 12 * (-0.75) = 60 = C4
440 Hz: MIDI = 69 + 12 * log2(440/440) = 69 + 0 = 69 = A4
523.25 Hz: MIDI = 69 + 12 * log2(523.25/440) = 69 + 3 = 72 = C5

Round the MIDI number to the nearest integer to get the nearest note. The decimal remainder tells you how many cents off-pitch the input frequency is (100 cents = 1 semitone).

Hz to Note Reference Chart

Common musical frequencies and their note equivalents.

NoteHzMIDI
C265.4136
E282.4140
F287.3141
A2110.0045
C3130.8148
E3164.8152
A3220.0057
C4261.6360
E4329.6364
A4440.0069
C5523.2572
A5880.0081
C61046.5084
E61318.5188

Frequency Ranges and What They Mean

Knowing what note a frequency corresponds to also tells you what register it sits in and how it behaves in a mix.

Sub Bass 20-60 Hz
Notes: Below E2

Felt more than heard. Kick rumble, sub-808 body. Use carefully.

Bass 60-250 Hz
Notes: E2 to B3

Fundamental bass lines, low end warmth. Fills mix with weight.

Low Mid 250-500 Hz
Notes: B3 to B4

Body of guitars, warmth of vocals. Can sound muddy if overcrowded.

Mid 500-2kHz
Notes: B4 to B6

Core vocal presence, guitar body, snare punch. Most ears are most sensitive here.

Upper Mid 2k-6kHz
Notes: B6 to D8

Vocal clarity, attack transients, consonants. Can cause ear fatigue.

High 6k-20kHz
Notes: D8+

Air, shimmer, hi-hat sizzle. Gives mix brightness and openness.

432 Hz vs 440 Hz: What Is the Difference?

Both are tunings for concert A. The difference is how the entire scale is calibrated:

440 Hz (Standard)
ISO 16 international standard since 1955
  • Used by virtually all modern instruments
  • Standard for orchestras, studios, DAWs
  • Tuning forks, piano tuning default
  • Universal compatibility with other musicians
432 Hz (Alternative)
Historical/alternative tuning, ~32 cents flat
  • Used before 1939 in some orchestras
  • Some music producers prefer the warmer tone
  • YouTube "432 Hz music" niche exists
  • Incompatible with 440 Hz instruments without retuning

In Hz-to-note terms: at 432 Hz tuning, A4 is 432 Hz instead of 440 Hz, and all other notes shift proportionally. Our converter uses the standard 440 Hz A4 reference.

When Producers Need Hz-to-Note Conversion

808 Tuning

Tune Your 808 to the Track Key

Find the BPM and key with BeatKey, then look up the exact Hz for that note, and pitch your 808 sample to match. Most 808 samples are rooted at C (around 65 Hz for C2). Use the chart to find the target Hz for any note in your key.

EQ and Notch Filtering

Remove Resonances Musically

When you find a resonant peak in a spectrum analyzer (e.g., 250 Hz), converting it to a note name tells you if it clashes with the track key. A resonance on D at 293 Hz in a song in C major may be intentional. One on Db might be worth notching.

Sample Flipping

Identify the Root Note of a Sample

Drop a sample into a spectrum analyzer, find the fundamental Hz, and convert it to the root note. Now you know exactly which note the sample is centered on and can pitch it to fit your key without guessing.

Noise and Hum

Identify Power Line Interference

US electrical hum is 60 Hz (Bb1). EU/UK hum is 50 Hz (G1). If you have hum in a recording, knowing the note name helps you understand if it is harmonically related to your song or a neutral frequency you can safely notch out.

Frequently Asked Questions

What note is 440 Hz?

440 Hz is A4, also called "concert A" or "concert pitch." It is the international standard tuning reference (ISO 16) used by orchestras and most modern instruments. When you tune a guitar, piano, or any instrument, A4=440 Hz is the starting reference point.

What note is 528 Hz?

528 Hz is approximately C5. The exact pitch of C5 at standard tuning is 523.25 Hz, so 528 Hz sits about 14 cents sharp of C5. It does not correspond to a standard piano note. Some call it a "Solfeggio frequency" but this has no basis in standard music theory or acoustic science.

What note is middle C in Hz?

Middle C (C4) is 261.63 Hz, or MIDI note 60. It is the C note in the fourth octave and sits at the center of an 88-key piano. Note: FL Studio displays middle C as C5 while Ableton and Logic display it as C4. The Hz value (261.63) is the same regardless of octave numbering convention.

How many Hz is one semitone?

There is no fixed Hz value for one semitone because semitone intervals are multiplicative, not additive. Each semitone multiplies the frequency by the twelfth root of 2 (about 1.0595). So from A4 (440 Hz), one semitone up is Bb4 at 466.16 Hz (+26.16 Hz). But from A5 (880 Hz), one semitone up is Bb5 at 932.33 Hz (+52.33 Hz). The Hz gap doubles with each octave.

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