π΅ Frequency to Note
Convert any Hz frequency to its nearest musical note.
How to Use This Calculator
Type any frequency in Hz into the input field and the converter instantly identifies the nearest musical note, shows you the exact equal-temperament frequency of that note, and tells you how many cents sharp or flat your input is from that note. Use the preset buttons for common reference pitches.
Type a frequency in the input box. You can enter whole numbers like 440 or decimals like 432.5. The range is 16 Hz to 20,000 Hz (the span of human hearing).
Read the note name in the large result display. It shows the note letter plus the octave number (for example, A4 for standard concert pitch).
Check the cents deviation. Plus cents means your frequency is sharp (higher than the note). Minus cents means it's flat. Within Β±5 cents is nearly perfect; beyond Β±20 cents sounds noticeably out of tune.
Use the preset buttons to explore reference pitches: middle C (C4) at 261.63 Hz, bass guitar low E (E1) at 41.2 Hz, or the full range of A notes from A0 to A6.
Equal Temperament Formula
The formula works by calculating how many semitones your frequency is above or below A4 (440 Hz). The result is the MIDI note number, which maps directly to a note name and octave. The cents deviation measures how far your frequency is from the exact equal-temperament pitch: there are 1200 cents per octave and 100 cents per semitone. If you're tuning an instrument or checking a recording, keep deviation within Β±5 to Β±10 cents for clean-sounding results.
Real-World Examples
When You Need This
Producers and sound designers frequently encounter raw frequency data. When you're synthesizing a bass note and want it to sit on a specific chord root, type the frequency you're hearing into this tool to confirm it matches the note you intend. A bass line that sits at 83 Hz is close to E2 (82.4 Hz) but 12 cents sharp, which can create subtle beating against a guitar part tuned precisely. Knowing the cents deviation lets you decide whether to nudge the oscillator or leave it.
Ear training students use frequency-to-note converters to study what specific pitches sound like. If you're learning to identify a concert A or training absolute pitch, you can generate tones at known frequencies (440, 493.88, 523.25) and practice labeling them before checking the result. Instrument builders and repair technicians also use this to check fork resonances and string vibrations against their target note frequencies without needing a separate chromatic tuner app.
Frequently Asked Questions
What is the frequency of A4?
A4 (the A above middle C) is standardized at 440 Hz in most modern music. Some orchestras tune to 441β443 Hz for a brighter sound. Baroque music often uses A=415 Hz (a semitone lower).
What is a cent in music?
A cent is 1/100th of a semitone, or 1/1200th of an octave. There are 100 cents between each adjacent note. Cents measure how sharp (+) or flat (β) a frequency is from the nearest equal-temperament note.
What is the lowest audible frequency?
Human hearing typically ranges from 20 Hz to 20,000 Hz. The lowest piano key (A0) is 27.5 Hz. The lowest note of a standard bass guitar is E1 at 41.2 Hz.
How do I calculate the note from a frequency?
n = 12 Γ logβ(f/440) + 69. Round to nearest integer for MIDI note number. n=69 is A4 (440 Hz). Each integer step is one semitone.
What is MIDI note number?
MIDI uses numbers 0β127. Middle C (C4) = MIDI 60. A4 = MIDI 69. The formula: MIDI = 12 Γ logβ(f/440) + 69. Each octave increases MIDI note by 12.