Musical Note Frequency Converter
Convert between musical notes and their frequencies in different octaves
Musical Note Frequency Converter
Enter a frequency between 16 Hz and 20,000 Hz (audible range)
Standard tuning: A4 = 440 Hz
Tuning Standards:
Common Presets:
Conversion Formula:
MIDI note = 12 × log₂(440.0/440) + 69 = 69
Details:
MIDI Note: 69
Piano Key: 49 (of 88)
Octave: 5
Wavelength: 0.780 m (in air at 20°C)
Period: 2.2727 ms
Sound Range: Lower midrange (cello, male voice)
Notation System:
Understanding Musical Frequency
Key Concepts:
- Pitch is the perceived frequency of sound
- Frequency is measured in Hertz (Hz, cycles per second)
- Each octave represents a doubling of frequency
- The equal-tempered scale divides each octave into 12 semitones
- A cent is 1/100 of a semitone (1200 cents = one octave)
- MIDI notes range from 0-127, with middle C (C4) as 60
Frequency Ranges:
- Human hearing: 20 Hz - 20,000 Hz
- Piano range: A0 (27.5 Hz) - C8 (4186 Hz)
- Bass instruments: 40 Hz - 300 Hz
- Mid-range: 300 Hz - 2000 Hz
- Treble/high frequencies: 2000 Hz - 10,000 Hz
- Vocal range: ~80 Hz - ~1100 Hz
Equal Temperament:
Modern Western music primarily uses 12-tone equal temperament (12-TET), where each octave is divided into 12 equal semitones. The frequency ratio between consecutive semitones is the 12th root of 2 (approximately 1.059463).
Formula for note frequency: f = fref × 2^(n/12), where fref is the reference frequency (usually A4 = 440 Hz), and n is the number of semitones from the reference note.
Musical Intervals and Frequency Ratios
| Interval | Semitones | Frequency Ratio | Example (from C4) |
|---|---|---|---|
| Unison | 0 | 1:1 | C4 to C4 |
| Minor Second | 1 | 16:15 | C4 to C#4/Db4 |
| Major Second | 2 | 9:8 | C4 to D4 |
| Minor Third | 3 | 6:5 | C4 to Eb4 |
| Major Third | 4 | 5:4 | C4 to E4 |
| Perfect Fourth | 5 | 4:3 | C4 to F4 |
| Perfect Fifth | 7 | 3:2 | C4 to G4 |
| Major Sixth | 9 | 5:3 | C4 to A4 |
| Major Seventh | 11 | 15:8 | C4 to B4 |
| Octave | 12 | 2:1 | C4 to C5 |
Waveform Options
Different waveforms produce different timbres when played through the visualization.
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Musical Note Visualization
Piano Keyboard
Click any key to hear its sound
Frequency Spectrum
Lower midrange
Waveform (sine)
Musical Context
Quick Reference
Middle C (C4): 261.63 Hz
Concert A (A4): 440 Hz
Octave: 2× frequency (12 semitones)
Semitone ratio: 2^(1/12) ≈ 1.0595
Concert Pitch Standards:
- Modern Standard: A4 = 440 Hz
- Baroque Period: A4 = 415 Hz
- Classical Period: A4 = 430 Hz
- Scientific/Verdi: A4 = 432 Hz
Instrument Frequency Ranges
| Instrument | Low Note | High Note | Freq. Range (Hz) |
|---|---|---|---|
| Piano | A0 | C8 | 27.5 - 4186 |
| Violin | G3 | E7 | 196 - 2637 |
| Guitar | E2 | E6 | 82.4 - 1319 |
| Flute | C4 | D7 | 262 - 2349 |
| Cello | C2 | C6 | 65.4 - 1047 |
| Soprano Voice | C4 | C6 | 262 - 1047 |
| Bass Voice | E2 | E4 | 82.4 - 330 |
Understanding Cents
A cent is a unit that measures the interval (pitch difference) between two notes. There are 100 cents in a semitone, and 1200 cents in an octave.
Cents are useful for describing:
- Microtonal music (intervals smaller than a semitone)
- Tuning discrepancies (how "sharp" or "flat" a note is)
- Non-Western musical scales
- Historical tuning systems
The human ear can typically detect a difference of about 5-10 cents between two notes.
About the Musical Note Frequency Converter
Convert between musical notes and their frequencies in different octaves All conversions run instantly in your browser and nothing you enter is sent to a server.
Common Conversion Formulas
| From | To | Formula |
|---|---|---|
| Note Frequency (Hz) | Reference Note (A4 = 440 Hz), Semitones (n) | f = 440 × 2^(n/12) |
| Octave Shift | Frequency (f), Octaves (o) | New Frequency = f × 2^o |
| MIDI Note Number | Frequency (f) | MIDI Number = 69 + 12 × log₂(f/440) |
| Wavelength (m) | Frequency (f), Speed of Sound (c = 343 m/s) | Wavelength = c / f |