86 free tools · runs in your browser
The modern toolbox for audio
Modern calculators, converters and live tools for audio people.
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Modern calculators, converters and live tools for audio people.
Press Ctrl / ⌘ K to search every tool
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The tools people reach for first
86 tools in 9 categories
dBu, dBV, dBm, dBFS, ratios, level sums and distortion.
Convert between dBu, dBV, dBm, volts RMS, volts peak-to-peak and power. Edit any field.
Convert decibels to voltage/pressure ratios, power ratios and nepers, and back.
Combine sound levels, add two coherent signals with a phase difference, or subtract background noise.
Convert THD, THD+N or noise figures between percent, dB, ratio and ppm.
Translate between dBu, dBV, dBFS, VU and PPM scales (DIN, EBU, BBC) for a chosen digital alignment.
Convert between peak, peak-to-peak, RMS and average values for sine, square and triangle waves.
Convert magnetic tape fluxivity in nWb/m to dB relative to a reference level.
Sound pressure, power, speed of sound, distance, weighting and loudness.
Predict how sound pressure, intensity and level drop as you move away from a point source.
Convert between delay time, distance and samples, with air temperature compensation.
Convert frequency to wavelength and period in air, with temperature compensation.
Convert between dB SPL, pascal, sound intensity, particle velocity and their levels.
From a source's sound power level to SPL at a distance, or back from a measurement.
Speed of sound from temperature, humidity and air pressure.
Convert a time delay into phase at a frequency, and into path length or samples.
High-frequency loss in air over distance, by frequency, temperature and humidity (ISO 9613-1).
Permissible daily exposure and noise dose for NIOSH, EU and OSHA criteria.
A- and C-weighting at any frequency, with curves and weighted levels.
Convert phon and sone, and see how much louder a level change sounds.
Convert Speech Transmission Index and articulation loss of consonants, with ratings.
Bandwidth, octave bands, RC and active filters, time constants.
Convert EQ Q to bandwidth in octaves, find the −3 dB edges, or the centre frequency from two edges.
Cutoff frequency and time constant of a first-order RC filter, or the resistor for a target cutoff.
Exact centre and edge frequencies of octave and third-octave bands, and combining band levels.
Convert time constants (µs) to corner frequencies, with FM, RIAA and CD emphasis values.
Component values for 12 dB/octave Sallen-Key low-pass, high-pass and band-pass filters.
Notes, cents, harmonics, chords and tempo-synced delays.
Delay times for every note value at any tempo, plus a tap-tempo counter.
Convert frequency, MIDI note and note name, with a full note table in English, German and Helmholtz notation.
Convert frequency ratios to cents and semitones, measure intervals, and compare just intervals with equal temperament.
The harmonic series of any fundamental with nearest notes and deviations in cents.
How much a wind instrument's pitch shifts when the air temperature changes.
Pick notes and get the chord name, including inversions and alternative readings.
Sensitivity, pickup patterns, stereo arrays and distances.
Explore omni, cardioid, hypercardioid and figure-8 patterns with directivity index and null angles.
Recording angle, ensemble fit and phantom source positions for XY, ORTF, NOS, DIN, Blumlein, AB or your own pair.
Where direct and reverberant sound are equally loud, and matching microphone distances per pattern.
Check whether your microphone spacing avoids audible comb filtering from leakage.
See the notches created when a signal is mixed with a delayed copy of itself.
Convert mV/Pa and dBV, and get output level, required gain, SNR and dynamic range for a given SPL.
The angle an ensemble covers from the microphone position, and the distance that matches a recording angle.
Room modes, reverberation time, materials and treatment design.
Find the resonant frequencies of a rectangular room and see where they cluster.
Per-octave reverberation time with Sabine and Eyring, using a library of typical absorption coefficients.
The frequency above which a room behaves statistically rather than modally.
Porous absorber thickness and perforated-panel resonator tuning for a target frequency.
Well depths for a quadratic residue (Schroeder) diffuser.
Convert reverberation time RT60 to decay rate in dB/s and to T20/T30 decay times.
Ohm's law, impedance, dividers, pads, cables, noise and data units.
Data rate and file size of uncompressed PCM audio for any sample rate, bit depth and channel count.
Total load of several speakers wired in series or in parallel.
Voltage, current, resistance and power from any two of them, e.g. amplifier watts into a speaker load.
Johnson noise of a resistor in µV and dBu, and how close a preamp's EIN is to the physical limit.
Output voltage, attenuation and impedances of a resistive divider, with or without load.
Series and parallel resistor values to attenuate a driver while keeping its impedance.
Capacitive and inductive reactance at a frequency, and the resonance of an LC pair.
How long cables and high source impedance roll off the treble.
Convert mm², diameter and AWG, and work out speaker-cable resistance, loss and damping factor.
Level loss between an output and an input, and how to measure output and input impedances.
Maximum SPL from sensitivity, amplifier power and distance; sensitivity ↔ efficiency; 2.83 V vs 1 W specs.
Read the value and tolerance of 4- and 5-band resistors.
Closest E6/E12/E24 value for a target, and the best series or parallel pair.
Convert bits, bytes, kB, KiB, MB, MiB, GB, GiB and data rates.
Resistor values for impedance-matched T, Pi, H and O attenuators.
Convert radio frequencies to wavelength, with half- and quarter-wave antenna lengths.
Generators, meters and analyzers that run in your browser.
Sine, square, sawtooth and triangle tones or a logarithmic sweep, with a safe output limit.
White, pink and brown noise for system alignment, room checks and masking.
Check left/right assignment and speaker polarity with pink noise.
RMS and peak level of your microphone in dBFS with clip warning.
Live log-frequency spectrum from your microphone with peak hold and peak frequency readout.
General unit converters, calendar, geometry and everyday maths.
Convert millimetres, centimetres, metres, inches, feet, yards and miles, including feet-and-inches.
Convert square metres, square feet, hectares, acres and more.
Convert litres, millilitres, cubic metres, cubic feet, and US and imperial gallons, pints and fluid ounces.
Convert milligrams, grams, kilograms, tonnes, ounces, pounds and stones.
Convert milliseconds, seconds, minutes, hours, days, weeks and years.
Convert Celsius, Fahrenheit, Kelvin, Rankine and Réaumur.
Convert pascal, hectopascal, bar, atmosphere, psi, Torr and mmHg.
Convert joules, watt-hours, kilowatt-hours, calories, BTU and electronvolts.
Convert watts, kilowatts, horsepower, PS and BTU per hour.
Convert m/s, km/h, mph, knots, feet per second and tape speeds in inches per second.
Convert m/s², g, ft/s² and Gal.
Convert newtons, kilonewtons, kilograms-force, pounds-force and dynes.
Convert kg/m³, g/cm³, lb/ft³ and lb per gallon.
Convert degrees, radians, gradians and turns, with sine, cosine, tangent and angle from a tangent.
Add up durations in h:mm:ss, for example track lengths for an album or a set list.
Weekday, ISO week, day of the year, leap year, days between two dates, and a date plus a number of days.
Percent of a value, one value as a percent of another, percentage change, and adding or removing a percentage.
Logarithms to any base, plus log₁₀, ln and log₂, and the inverse powers.
Solve a·x² + b·x + c = 0 with real or complex solutions, discriminant and vertex.
Check whether a number is prime and get its prime factors, divisors and neighbouring primes.
Convert numbers to Roman numerals and back (1 to 3999).
Area, perimeter, volume and surface of rectangles, triangles, circles, cuboids, spheres, cylinders and cones.
Checked against real numbers.
Every formula has automated tests that compare it with published reference values, standards tables and independent calculators.
Understand the maths behind them
Three different jobs and the tools for each.
Reverberation-chamber measurement, edge effects and practical coefficients.
What does and does not work in room treatment.
How decibels add for independent and related signals.
Voltage sources, nominal impedance, damping factor, bi-wiring and bi-amping.
Short definitions of terms used across the site.
Everything is free and there are no accounts. Your favorites and your light or dark choice are stored only in your own browser.
No. The level meter and spectrum analyzer process sound locally with the Web Audio API and never send it anywhere. Browsers only allow microphone access on secure (HTTPS) pages.
Formulas are tested against published reference values. Some tools are models rather than exact laws: the stereo recording angle, the absorption coefficients in the RT60 tool and the speaker maximum SPL are estimates. Use the results as guidance and verify critical values.
A and C weighting follow IEC 61672-1, air absorption follows ISO 9613-1, octave bands follow IEC 61260, and the speed of sound in humid air uses Cramer's equation.
They start quiet (−30 dBFS) and are capped at −6 dBFS. Raise your own system volume gradually, especially with sine waves and square waves, which can damage tweeters and hearing at high levels.