About the Audio File Size Calculator
This audio file size calculator estimates how much storage a recording or export will take. For uncompressed formats such as WAV and AIFF, enter the sample rate, bit depth, number of channels and duration; for compressed formats like MP3, AAC, Ogg or Opus, enter the bitrate instead. You can multiply by a number of tracks to size a whole album, multitrack session or podcast season.
It helps recording engineers plan drive space for multitrack sessions, podcasters choose export settings, musicians check upload limits on distribution platforms and anyone comparing formats. The chart compares your length at common formats so you can see how much space lossless audio costs compared with compressed audio.
Uncompressed PCM size is exact apart from a small file header (about 44 bytes for a basic WAV). Compressed sizes assume a constant bitrate; variable-bitrate files land near the average bitrate. Results are shown in decimal megabytes (1 MB = 1,000,000 bytes) as used by drive makers and macOS, and in binary mebibytes (1 MiB = 1,048,576 bytes) as shown by Windows.
With the default inputs, the total size is 37.04 MB. Change any value above to recalculate instantly.
How to use the audio file size calculator
- 1Choose uncompressed (WAV/AIFF) or compressed (MP3/AAC) audio.
- 2For WAV/AIFF pick the sample rate, bit depth and channels; for MP3/AAC enter the bitrate.
- 3Enter the duration in hours, minutes and seconds.
- 4Set the number of tracks if you are sizing an album or multitrack session.
- 5Read the size in MB or GB and compare formats in the chart.
Formula and method
Uncompressed PCM audio stores one sample per channel for every tick of the sample rate, and each sample uses the chosen number of bits. Multiplying sample rate × bit depth × channels gives the bitrate in bits per second (1,411.2 kbps for CD audio); multiplying by the duration and dividing by 8 converts bits to bytes.
Compressed formats are described directly by their bitrate, so size is simply bitrate × time ÷ 8. A kilobit here is 1,000 bits, as used by encoders. The file header and metadata such as cover art add a little on top, usually a few kilobytes to a few hundred kilobytes.
- sample rate
- Samples per second per channel, e.g. 44,100 or 48,000
- bit depth
- Bits per sample, e.g. 16 or 24
- bitrate
- Bits per second for all channels together (kbps × 1,000)
Worked examples
3:30 song as a CD-quality WAV
44,100 × 16 × 2 = 1,411,200 bits per second. Over 210 seconds that is 296,352,000 bits, or 37,044,000 bytes — about 37.0 MB (35.3 MiB in Windows).
4-minute MP3 at 320 kbps
320,000 bits per second × 240 seconds ÷ 8 = 9,600,000 bytes, or 9.6 MB. Each minute of a 320 kbps MP3 takes 2.4 MB.
24-track session at 24-bit/48 kHz, 1 hour
Each mono track is 48,000 × 24 = 1,152,000 bits per second, or 518.4 MB per hour. Twenty-four tracks for an hour need 24 × 518.4 MB ≈ 12.44 GB of drive space.
Frequently asked questions
How big is a 1-minute WAV file?+
At CD quality (44.1 kHz, 16-bit, stereo) one minute is about 10.58 MB. At 24-bit/48 kHz stereo it is about 17.28 MB, and at 24-bit/96 kHz stereo about 34.56 MB.
How big is a 3-minute MP3?+
At 320 kbps a 3-minute MP3 is about 7.2 MB; at 192 kbps about 4.3 MB; at 128 kbps about 2.9 MB. Embedded cover art can add a few hundred kilobytes.
Why does Windows show a smaller size than my calculation?+
Windows reports sizes in binary units (1 MB shown = 1,048,576 bytes), while this calculator’s main figure uses decimal megabytes (1,000,000 bytes). Compare with the MiB result instead.
Does stereo double the file size?+
For uncompressed audio, yes — two channels store twice as many samples as mono. For MP3 and AAC the bitrate is shared between channels, so the size depends only on the bitrate you choose.
How much space does a 24-bit recording session need?+
Each mono track at 24-bit/48 kHz uses about 518 MB per hour. Multiply by the number of tracks: a 16-track hour is about 8.3 GB, before any extra takes.