Music & Audio
Music and audio math — note frequencies, tempo delays, intervals, and sample sizes.
12 tools
Note to Frequency Calculator
Frequency of any musical note, and the nearest note to a frequency.
Tempo to Delay Calculator
Delay and note-value times in milliseconds from a tempo in BPM.
Musical Interval Calculator
Frequency ratio and cents between two notes or a semitone count.
Audio File Size Calculator
Uncompressed audio file size from sample rate, bit depth, and length.
Harmonic Series Calculator
Overtone frequencies of the harmonic series from a fundamental.
Music Transposition Calculator
Transpose a note or key by a number of semitones.
Metronome
A free online metronome with adjustable BPM, time signature, and tap tempo.
Chord Finder
Find the notes in any chord from its root and quality — triads to 7ths and more.
Scale Finder
Find the notes of any scale or mode from its root — major, minor, modes, pentatonic.
Circle of Fifths
Key signatures, sharps and flats, and relative minors for all 12 keys.
Frequency to Note
Convert a frequency in Hz to the nearest note and cents deviation.
Decibel Calculator
Convert ratios to decibels and back, and add sound levels in dB.
About music & audio tools
The math behind music and audio — note-to-frequency (A4 = 440 Hz, 12-tone equal temperament), tempo-to-delay times, interval ratios and cents, the harmonic series, sample-size estimates, and transposition. Each tool shows the formula and the working, for producers, students, and instrument builders.
When to use these tools
Common music & audio tasks and the tool that handles each one.
Frequently asked questions
Common questions about music & audio — the concepts behind the tools above.