Note Frequency Guide
How to use musical note frequencies in mixing, production, and sound design. For DJs and producers who want to go deeper than just "it sounds right."
The A440 Standard
Every note frequency is built on one reference: A4 = 440 Hz. This is defined by ISO 16 (1975) and is the tuning standard used globally in orchestras, DAWs, hardware synthesizers, and digital tuners.
Before standardization, different orchestras tuned A to different pitches (anywhere from 415 Hz to 466 Hz historically). The 440 Hz standard means that a violin in Berlin, a piano in Tokyo, and a softsynth in Toronto all agree on where A4 lives. When you produce music, your DAW defaults to A4 = 440 Hz unless you change it.
Some producers tune to A4 = 432 Hz (claimed to be "more natural"). There is no scientific basis for this having a perceptual effect, but if you are working with stems from a 432 Hz project, every note will be slightly flat relative to 440 Hz standard tools. The frequency calculator above uses the 440 Hz standard.
Equal Temperament and the 12-TET Formula
Modern music uses 12-tone equal temperament (12-TET). The octave is divided into 12 equal semitones. "Equal" here means each semitone has the same frequency ratio to the next: the 12th root of 2, or approximately 1.05946.
- f = frequency in Hz
- n = MIDI note number (A4 = 69, middle C = 60)
- 440 = A4 reference frequency
- 69 = MIDI note number of A4
Examples: C4 (MIDI 60) = 440 x 2^((60-69)/12) = 440 x 2^(-0.75) = 261.63 Hz. A5 (MIDI 81) = 440 x 2^((81-69)/12) = 440 x 2^1 = 880 Hz.
Octaves, Semitones, and Cents
Three frequency relationships every producer should know:
A3 = 220 Hz, A4 = 440 Hz, A5 = 880 Hz. Each octave doubles. This is why bass notes at 60 Hz and their higher harmonics at 120 Hz, 240 Hz, 480 Hz all "belong" to the same note.
Moving up one semitone from A4 (440 Hz) gives A#4 (466.16 Hz). Moving down one semitone gives G#4 (415.30 Hz). Pitch-shift +1 semitone in your DAW = multiply Hz by 1.05946.
100 cents = 1 semitone. Detuning an oscillator by 5-15 cents creates chorus/detune effects. The frequency calculator above shows cents deviation when a frequency is between two notes.
Practical Use: Tuning 808s and Bass Lines
The most common use of note frequencies in production: tuning 808 kicks to match your track's key.
- Find your track's key using a BPM and key detector. Let's say it detects F# minor.
- Find your 808's root note. Most 808 samples default to C or G. Check your sampler or pitch detection (drop it into BeatKey). Let's say it's C2 (65.41 Hz).
- Count the semitones from C to F#. That's 6 semitones up.
- Pitch-shift +6 semitones in your DAW's sampler. Your 808 now plays F#2 (92.50 Hz), locking it to the track's key.
- Verify. Enter 92.50 into the frequency to note converter above. It should return F#2.
Practical Use: EQ by Note Fundamentals
When you know what note a sound is playing, you can EQ more precisely:
If your kick has heavy energy at C2 (65 Hz) and your bassline is also in C, they will mask each other. High-pass your bass above 65 Hz to let the kick's fundamental through. Or notch the bass at 65 Hz and boost at 130 Hz (C3, one octave up) to keep the note recognizable but less conflicting.
A note's harmonics occur at 2x, 3x, 4x, 5x the fundamental. C2 at 65 Hz has harmonics at 130 Hz, 196 Hz, 261 Hz, 327 Hz... Boosting at harmonic frequencies adds "body" without making the sound muddy, because you're reinforcing naturally occurring resonances.
Dynamic EQ and multiband compressors work best when the detection filter is tuned to the source note. If you want your bass to duck when the kick hits, tune the sidechain detector to the kick's fundamental frequency (look it up in the table) so it triggers on the right energy.
Frequently Asked Questions
What is the frequency of every note on a piano?
Piano notes range from A0 (27.50 Hz) to C8 (4186.01 Hz). The most-used reference: A4 = 440 Hz (concert pitch), C4 (middle C) = 261.63 Hz. Use the full frequency table on the main calculator page at notes.beatkey.app.
How do I tune an 808 to a key?
Find the key of your track with BeatKey (beatkey.app). Find the root note of your 808 (drop it into BeatKey or check your sampler). Count the semitones between the 808 root and your track root, then pitch-shift by that number in your DAW sampler.
What Hz is low end bass?
Sub-bass lives below 60 Hz. Deep bass fundamentals (C2 = 65 Hz, B1 = 62 Hz) sit at the edge of sub-bass. Standard bass guitar low E (E2) is 82 Hz. Most 808 kicks have fundamental energy between 40-100 Hz depending on pitch. High-pass at 20-30 Hz removes subsonic noise without affecting the bass note.
What is equal temperament tuning?
Equal temperament (12-TET) divides each octave into 12 equal semitones, each with a ratio of the 12th root of 2 (approximately 1.05946). This is the standard tuning system used in all modern DAWs, hardware synths, and electronic instruments. All calculations in this tool use 12-TET with A4 = 440 Hz.
Use the interactive calculator to convert any note to Hz or find a note from a frequency.
Open Note Frequency Calculator