Frequency to Note Converter
Enter any frequency in Hertz (Hz) and instantly find its closest musical note, octave, and tuning deviation in cents.
🎵 Frequency → Note Converter
Enter any frequency in Hertz (Hz) and instantly find its closest musical note, octave, and tuning deviation in cents.
How It Works
This tool translates a physical measurement (frequency) into a musical concept (a note) using a standard tuning system.
The conversion relies on the logarithmic relationship between frequency and pitch. All calculations are based on 12-Tone Equal Temperament (12-TET), where the A above middle C (A4) is standardized at 440 Hz. The mathematical formula used is n = 12 × log₂(f / 440) + 69, where ‘f’ is the frequency you enter and ‘n’ is the resulting MIDI note number. This number is then mapped to its corresponding note name (e.g., C4, F#5).
The tool also calculates the precise deviation from the perfect pitch of the target note, measured in cents. A cent is 1/100th of a semitone, allowing for extremely fine pitch measurements. Every calculation happens instantly and securely in your browser — no uploads or data collection.
Common Frequencies & Notes
To give you a practical reference, here is a chart of standard frequencies for notes in the middle octaves of a piano, based on the A4 = 440 Hz standard.
| Note | Frequency (Hz) | Octave |
|---|---|---|
| C3 | 130.81 Hz | 3 |
| G3 | 196.00 Hz | 3 |
| C4 (Middle C) | 261.63 Hz | 4 |
| D4 | 293.66 Hz | 4 |
| E4 | 329.63 Hz | 4 |
| F4 | 349.23 Hz | 4 |
| G4 | 392.00 Hz | 4 |
| A4 (Standard) | 440.00 Hz | 4 |
| B4 | 493.88 Hz | 4 |
| C5 | 523.25 Hz | 5 |
| E5 | 659.26 Hz | 5 |
| G5 | 783.99 Hz | 5 |
Reading the Results
The converter provides three key pieces of information to help you understand the pitch of your frequency.
Note Name
This is the closest standard musical note in the 12-tone scale (e.g., A4, C#5). It represents the nearest perfect semitone to the frequency you entered.
Cents Deviation
This value shows the fine-tuning offset from the perfect pitch of the displayed note. A positive value means the frequency is sharp (higher), and a negative value means it is flat (lower).
Example: If you enter 443 Hz, the tool will show: A4 (+11.73 cents), with a status of “Slightly Sharp.” This tells you the frequency is very close to A4, but just a little higher in pitch. The green “In Tune” status appears for deviations within ±5 cents.
Accuracy & Methodology
Our commitment is to provide precise and trustworthy results based on established music theory and secure technology.
All calculations adhere strictly to the 12-Tone Equal Temperament (12-TET) system and use the A4 = 440 Hz standard, compliant with ISO 16. The mathematical precision of the tool is extremely high, with an accuracy of approximately ±0.1 Hz and ±1 cent, ensuring reliable results for academic and professional use.
Every calculation is performed locally on your device. No data is ever sent to our servers. While the theoretical values are precise, they may differ slightly from the pitch of a live acoustic instrument due to physical imperfections. For more information, please see our technical methodology.
Use Cases
This converter is a valuable tool for a wide range of audio professionals, students, and enthusiasts.
- 🎤 Singers – Find the exact target frequency for a note you want to practice hitting perfectly.
- 🎹 Musicians – Verify the frequency of a reference tone when tuning instruments by ear.
- 🎧 Producers & Engineers – Identify the musical note of a synth patch or an 808 sample based on its fundamental frequency.
- 🧑🏫 Teachers & Students – Visually demonstrate the direct mathematical relationship between Hertz and musical notes.
- 🔬 Researchers – Quickly map measured frequencies from various audio signals back to standard musical notation.
Practical Tips
Get the most accurate and useful results from the converter with these simple tips.
- Use frequencies within the typical human hearing range (20 Hz to 20,000 Hz) for the most meaningful musical results.
- Ensure the A4 reference in the tool matches the tuning standard of any instruments or software you are comparing against.
- If measuring a live instrument’s frequency, try to get an average reading, as pitch can fluctuate slightly.
- For the best performance and compatibility, use the latest version of a modern browser like Chrome, Edge, or Safari.
- Pair this tool with our live Pitch Detector to find a frequency, then enter it here for a detailed breakdown.
Limitations
While highly accurate, this tool has specific limitations based on the principles of music theory.
This converter is designed for single, clean frequencies. It is not intended for analyzing complex audio that contains multiple notes at once (chords or full songs). It assumes the input is a fundamental frequency and does not account for overtones or harmonics.
Furthermore, all calculations are based on the theoretical perfection of 12-Tone Equal Temperament. This may differ from other tuning systems, such as Just Intonation or historical temperaments. While you can adjust the A4 reference, the relative spacing of the notes remains fixed to the 12-TET standard.
Frequently Asked Questions
How does this converter work?
The tool uses a mathematical formula based on 12-Tone Equal Temperament to convert a frequency in Hertz (Hz) into its nearest corresponding musical note. It also calculates the precise deviation in cents (1/100th of a semitone).
Can I change the tuning reference from A4 = 440 Hz?
Yes, you can select common alternative tuning references like 442 Hz (often used by orchestras) directly in the tool to ensure the results match your specific context.
Is this accurate enough for tuning professional instruments?
Yes, the mathematical accuracy is extremely high (±1 cent). It provides the theoretical perfect pitch for any note, making it an excellent reference for calibrating electronic tuners or setting up synthesizers.
What is the difference between pitch and frequency?
Frequency is the scientific measurement of a sound wave’s vibrations, measured in Hertz (Hz). Pitch is the musical term for how high or low we perceive that sound to be. This tool translates the objective measurement (frequency) into the subjective musical concept (pitch/note).
Does this tool store my input data?
No. All calculations are performed locally in your browser. No data, including the frequencies you enter, is ever sent to or stored on a server. Your privacy is 100% protected.
Can I use it on mobile?
Yes, this tool is fully responsive and designed to work perfectly on all modern devices, including smartphones, tablets, and desktops.