How it works
Choose sample rate, bit depth, channel count and duration. Payload bytes = frames × channels × bits/8. Container metadata is additional.
Worked example
Three minutes of 48 kHz, stereo, 24-bit PCM is 51.84 MB (about 49.44 MiB), before headers. Variable-bitrate MP3 or compressed FLAC size cannot be predicted by this formula.
Read the result
PCM storage grows with frames per second, bits per sample, channel count and duration. The result separates decimal MB from binary MiB and excludes container headers. It is a budgeting estimate for uncompressed PCM, not a forecast for every codec.
Common mistakes
Do not use the PCM formula to predict a FLAC or variable-bitrate MP3 file. Do not confuse bits with bytes or stereo frames with individual channel samples. Increasing bit depth in a conversion does not recover detail lost in the source.
Questions musicians ask
How to calculate audio file size?
For PCM payload, multiply sample rate by duration, channels and bit depth, then divide by eight to convert bits to bytes. A 180-second stereo recording at 48,000 Hz and 24 bits produces 51,840,000 payload bytes, before headers.
What is audio bit depth?
Bit depth describes the precision of each PCM sample's stored value. It is separate from sample rate and from an MP3 bitrate. This calculator uses the selected integer storage width, not an estimated perceptual quality score.
What is sample rate in audio?
Sample rate is the number of sample frames per second. A stereo frame contains one value for each channel. MDN's AudioBuffer documentation distinguishes sample rate, frame length, channel count and duration.
Sources and calculation notes
From measurement to mastering
Understand the measurement, then compare your own mix and reference. Your ears remain the final judge.