Note Frequency Chart
A complete reference table of musical note frequencies from C0 (16.35 Hz) to B8 (7902.13 Hz) calculated using 12-tone equal temperament with A4 tuned to 440 Hz. Each row shows the note name, octave, precise frequency in Hertz, and MIDI note number. Click the play button next to any note to hear its pitch through your speakers. This chart is an essential reference for musicians, audio engineers, synthesizer programmers, and anyone working with sound.
How Note Frequency Chart Works
Complete frequency chart for all musical notes C0 to B8 in equal temperament. See Hz values, MIDI numbers, and play any note. A440 reference. Use the tool above to get your results instantly — everything runs in your browser with no data sent to any server.
Understanding Equal Temperament Tuning
Equal temperament is the tuning system used in virtually all modern Western music. It divides the octave into twelve exactly equal semitones, where each semitone has a frequency ratio of the twelfth root of two (approximately 1.05946). This means every note is related to every other note by the same mathematical ratio, allowing music to be played in any key without retuning the instrument. The formula for any note's frequency is f = 440 * 2^((n - 69) / 12), where n is the MIDI note number and 69 corresponds to A4 at 440 Hz.
Before equal temperament became standard in the 18th and 19th centuries, various tuning systems were used, each optimizing certain intervals at the expense of others. Pythagorean tuning based intervals on perfect fifths, just intonation used pure frequency ratios for consonant intervals, and meantone temperament compromised between the two. Each system sounded beautiful in certain keys but noticeably out of tune in others. Equal temperament sacrificed the purity of individual intervals for the practical advantage of consistent intonation across all twelve keys — a trade-off that enabled the harmonic complexity of modern music.
The A440 Concert Pitch Standard
The reference pitch A4 = 440 Hz is the international standard for musical tuning, adopted by the International Organization for Standardization in 1955 (ISO 16). This means that when an orchestra tunes, they tune to an A at 440 Hz, and all other note frequencies derive from this reference. However, concert pitch has not always been 440 Hz. Historical evidence shows that pitch standards varied widely: Baroque ensembles typically tuned to A415 (a semitone below modern pitch), while some 19th-century orchestras tuned as high as A450. Even today, some orchestras tune to A442 or A443 for a slightly brighter sound. The frequency chart on this page uses the standard A440 reference.
How Octaves and Frequency Relate
The most fundamental relationship in music is the octave: doubling a frequency raises the pitch by exactly one octave. A4 at 440 Hz becomes A5 at 880 Hz, A6 at 1760 Hz, and so on. Going down, A3 is 220 Hz, A2 is 110 Hz, and A1 is 55 Hz. This doubling relationship is consistent across all notes — C4 (middle C) at 261.63 Hz becomes C5 at 523.25 Hz. This is why octave equivalence exists in music perception: notes an octave apart sound fundamentally similar, just higher or lower. The human hearing range spans roughly 20 Hz to 20,000 Hz, encompassing about ten octaves of the musical spectrum.
MIDI Note Numbers Explained
MIDI (Musical Instrument Digital Interface) assigns each note a number from 0 to 127, covering the range from C-1 (8.18 Hz) to G9 (12,543.85 Hz). Middle C (C4) is MIDI note 60, and A4 is MIDI note 69. Each semitone increments the MIDI number by one. MIDI numbers are essential for digital music production, allowing synthesizers, samplers, and software instruments to communicate pitch information precisely. When you press a key on a MIDI keyboard, the note number is transmitted as a data message, and the receiving instrument converts it to the appropriate frequency for playback.
Practical Uses of the Frequency Chart
Audio engineers use frequency charts to identify problem frequencies in a mix — knowing that the muddiness in a vocal might be around 250 Hz (approximately B3) helps them target the right frequency band with an equalizer. Synthesizer programmers reference these values when designing sounds, setting filter cutoffs to specific musical notes, or tuning oscillators. Guitar players check their tuning against exact frequencies. Sound designers working with Foley and sound effects use the chart to pitch-shift recordings to match musical elements in a film score. Anyone working with audio benefits from understanding the relationship between musical notes and their frequencies.
2026 ISO 16 Concert Pitch Standard and A440 Reference
The official concert-pitch standard for 2026 remains ISO 16:1975 — Acoustics: Standard Tuning Frequency (Standard Musical Pitch), which fixes A4 at exactly 440.00 Hz. This standard was reaffirmed by the International Organization for Standardization in its most recent technical review and continues to govern tuning across orchestral, recording, and broadcast applications worldwide. The American National Standards Institute mirrors this in ANSI S1.1 acoustical terminology, and the MIDI 2.0 specification published by the MIDI Association locks MIDI note 69 to 440 Hz as the reference for software synthesizers and digital audio workstations. While some orchestras (notably the Berlin and Vienna Philharmonics) tune slightly sharper at A442 to A444 for tonal brightness, the international ISO 16 baseline of A440 is what every chart on this page, every digital tuner, and every modern DAW uses by default. To use this reference data inside your own tracks, pair the chart with the interval calculator for note-to-note frequency ratios, the key signature finder when transposing, and the chord progression generator when sketching new ideas.
2026 Note Frequency Chart for Instrument Tuning
For 2026 tuning practice, the standard reference notes per ISO 16 equal temperament are: A4 = 440.00 Hz (concert pitch), middle C (C4) = 261.63 Hz, the lowest piano note A0 = 27.50 Hz, the highest C8 = 4186.01 Hz, MIDI 0 (C-1) = 8.18 Hz, and MIDI 127 (G9) = 12,543.85 Hz. Standard guitar tuning maps to E2 (82.41 Hz), A2 (110.00 Hz), D3 (146.83 Hz), G3 (196.00 Hz), B3 (246.94 Hz), and E4 (329.63 Hz). Bass guitar standard tuning is one octave lower at E1 (41.20 Hz), A1, D2, and G2. Violin tuning fits the perfect-fifth pattern G3, D4, A4, E5, while cello tunes C2, G2, D3, A3. For practice timing while tuning by ear, use the practice timer; for tempo locking against a click track, the BPM tapper and BPM to ms converter let you align delay-line timing to your project tempo, and the time signature explainer covers the rhythmic side once tuning is locked in. Last updated 2026-05-05 with ISO 16:1975 Standard Musical Pitch and MIDI 2.0 specification.
Frequently Asked Questions
What frequency is middle C?
Middle C, also known as C4, has a frequency of approximately 261.63 Hz in standard A440 equal temperament tuning. It corresponds to MIDI note number 60 and is the reference point for the standard music notation system.
Why is A4 tuned to 440 Hz specifically?
The A440 standard was established by international agreement in 1955 as a compromise between various national standards that ranged from 435 to 450 Hz. It provides a bright, clear reference that works well for most instruments and voices. Some argue for alternative standards like 432 Hz, but 440 Hz remains the universal default.
Can I hear notes below 20 Hz on this chart?
Notes below approximately 20 Hz (like C0 at 16.35 Hz) fall below the threshold of human hearing. While your speakers may produce vibrations at these frequencies, you will perceive them as a rumble or physical sensation rather than a distinct pitch. Most consumer speakers cannot reproduce frequencies this low accurately.
What is the difference between equal temperament and just intonation?
Equal temperament divides the octave into 12 exactly equal semitones, making all keys equally in tune (or equally slightly out of tune). Just intonation uses pure frequency ratios like 3:2 for fifths and 5:4 for major thirds, which sound more consonant in isolation but cause certain keys to sound noticeably out of tune. Equal temperament is the standard for modern fixed-pitch instruments.
How do I use this chart for EQ in music mixing?
Identify the fundamental frequency of the instrument or vocal you are working with, then use the chart to understand which notes fall in different frequency ranges. For example, if a bass guitar sounds muddy, you know its fundamentals are roughly 40-100 Hz (E1 to G2), so cutting around 200-300 Hz (G3 to D4) reduces muddiness without losing the fundamental tone.
What is the official ISO 16 concert pitch standard for 2026?
The current international standard is ISO 16:1975 — Acoustics: Standard Tuning Frequency (Standard Musical Pitch), which fixes A4 at exactly 440.00 Hz. This was most recently reaffirmed by the International Organization for Standardization and remains the 2026 baseline. ANSI S1.1 mirrors this for North America, and MIDI 2.0 locks MIDI note 69 to 440 Hz for digital instruments. Some orchestras tune to A442-A444 for brightness, but every digital tuner, DAW, and frequency chart on this page uses the ISO 16 A440 default.
What are the standard tuning frequencies for guitar, bass, violin, and cello in 2026?
Standard 6-string guitar (low to high): E2 = 82.41 Hz, A2 = 110.00 Hz, D3 = 146.83 Hz, G3 = 196.00 Hz, B3 = 246.94 Hz, E4 = 329.63 Hz. 4-string bass (one octave below guitar): E1 = 41.20 Hz, A1 = 55.00 Hz, D2 = 73.42 Hz, G2 = 98.00 Hz. Violin (perfect fifths): G3, D4, A4 (440 Hz), E5. Cello (perfect fifths): C2, G2, D3, A3. All values assume A4 = 440 Hz equal temperament tuning per ISO 16:1975.