🎵 Note Frequency Finder
Find exact frequencies for musical notes in Hz. Select any note from C0 to B8 across all octaves and see its precise frequency based on A4=440Hz tuning.
Your Result:
Example Results:
A4: 440.00 Hz
C4 (Middle C): 261.63 Hz
E4: 329.63 Hz
G4: 392.00 Hz
How to Use This Note Frequency Finder
Using the Note Frequency Finder is straightforward and provides instant, precise frequency calculations for any musical note.
- Select your note: Choose from the 12 chromatic notes (C, C#/Db, D, D#/Eb, E, F, F#/Gb, G, G#/Ab, A, A#/Bb, B). Enharmonic equivalents like C# and Db are shown together for convenience.
- Choose the octave: Select from octaves 0-8, with octave 4 containing Middle C. The standard piano spans from A0 to C8, while electronic instruments often extend this range.
- Set tuning frequency: Adjust the A4 reference frequency if needed. The default 440 Hz is the international standard, but you can use values from 400-480 Hz for different tuning systems or historical performance practices.
- Get instant results: The tool immediately calculates and displays the exact frequency in Hz with high precision, making it perfect for instrument tuning, audio production, and educational purposes.
The frequency values are calculated using equal temperament tuning, where each semitone represents a frequency ratio of 2^(1/12). This mathematical precision ensures accurate results for professional audio work, scientific applications, and musical analysis.
How It Works
The Note Frequency Finder uses the mathematical principles of equal temperament to calculate precise frequencies for musical notes.
- Equal temperament system: Each semitone (half-step) represents a frequency ratio of exactly 2^(1/12) ≈ 1.05946. This creates 12 equally spaced notes within each octave, making all keys sound equally in tune.
- MIDI note calculation: The tool first converts your note and octave selection to a MIDI note number using the formula: MIDI = (octave + 1) × 12 + note_offset, where A4 = MIDI note 69.
- Frequency calculation: Using the MIDI note number, the frequency is calculated as: frequency = A4_tuning × 2^((MIDI_note - 69) / 12). This formula works for any reference tuning, not just A4=440 Hz.
- Precision and rounding: Results are calculated with high mathematical precision and displayed to two decimal places for practical use. The underlying calculations maintain full precision for accurate professional applications.
- Octave relationships: Each octave represents a doubling of frequency. A4 (440 Hz) becomes A5 (880 Hz) in the next octave and A3 (220 Hz) in the previous octave, maintaining perfect 2:1 ratios.
When You Might Need This
- • Musicians tuning instruments to precise frequencies
- • Audio engineers setting up synthesizers and electronic instruments
- • Music producers working with frequency-based effects and filters
- • Sound designers creating specific tones for audio projects
- • Music theory students learning the mathematical relationships between notes
- • Instrument technicians calibrating pianos and other pitched instruments
- • Audio software developers implementing note detection algorithms
- • Music educators teaching frequency relationships and equal temperament
- • Composers working with microtonal music and alternative tunings
- • Audiophiles and hi-fi enthusiasts testing speaker frequency response
Frequently Asked Questions
What is the standard tuning frequency for A4?
The standard tuning frequency for A4 is 440 Hz, established as the international pitch standard. However, some orchestras use 441-444 Hz, and historical tunings like A4=415 Hz are used for period performances. Our tool allows you to adjust the A4 reference frequency to calculate notes for any tuning system.
How are musical note frequencies calculated?
Note frequencies are calculated using equal temperament, where each semitone is exactly 2^(1/12) ≈ 1.05946 times the frequency of the previous semitone. Starting from a reference frequency (usually A4=440 Hz), we can calculate any note by determining how many semitones it is from A4 and applying the formula: frequency = 440 × 2^((n-69)/12), where n is the MIDI note number.
What is the frequency range covered by this tool?
This tool covers the full range from C0 (16.35 Hz) to B8 (7902.13 Hz), spanning 9 octaves and 108 semitones. This range covers all notes on a full 88-key piano plus extended ranges used in electronic music and sound design. The lowest notes are felt more than heard, while the highest notes approach the upper limits of human hearing.
Can I use different tuning systems besides A4=440 Hz?
Yes, you can adjust the A4 tuning frequency from 400 Hz to 480 Hz to accommodate different tuning standards. Common alternatives include A4=442 Hz (used by many European orchestras), A4=432 Hz (popular in some alternative tuning movements), and A4=415 Hz (Baroque pitch for historical performance). The tool recalculates all frequencies proportionally based on your chosen A4 reference.
Why do some notes show the same frequency in different octaves?
Notes in different octaves don't show the same frequency - each octave doubles the frequency. For example, A4 is 440 Hz, A5 is 880 Hz, and A3 is 220 Hz. If you're seeing identical frequencies, check that you've selected different octave numbers. The octave number changes at C, so B3 is followed by C4, not C3.