How big are audio files? An uncompressed stereo WAV at CD quality (44.1 kHz, 16-bit) takes about 10.6 MB per minute, a 24-bit 48 kHz stereo WAV about 17.3 MB per minute, and a 320 kbps MP3 about 2.4 MB per minute. The size depends on sample rate, bit depth, channel count and length, plus the format. The free audio file size calculator works out WAV, FLAC and MP3 sizes for any settings.
The formula for uncompressed audio
WAV and AIFF files store every sample, so their size is simple to predict:
bytes = sample rate × (bit depth ÷ 8) × channels × seconds
Divide the result by 1,000,000 for megabytes. For one minute of CD-quality stereo: 44,100 × 2 × 2 × 60 = 10,584,000 bytes, or 10.58 MB. The same calculation gives the bit rate: 44,100 × 16 × 2 = 1,411,200 bits per second, the familiar 1,411 kbps.
WAV sizes per minute
| Format | Stereo, per minute | Mono, per minute |
|---|---|---|
| 44.1 kHz / 16-bit | 10.58 MB | 5.29 MB |
| 44.1 kHz / 24-bit | 15.88 MB | 7.94 MB |
| 48 kHz / 24-bit | 17.28 MB | 8.64 MB |
| 48 kHz / 32-bit float | 23.04 MB | 11.52 MB |
| 96 kHz / 24-bit | 34.56 MB | 17.28 MB |
| 192 kHz / 24-bit | 69.12 MB | 34.56 MB |
Doubling the sample rate doubles the size, and going from 16-bit to 24-bit adds half again.
Compressed formats: FLAC and MP3
- FLAC is lossless: it decodes back to exactly the same audio as the WAV. It usually ends up around 50 to 60% of the WAV size, depending on how dense the music is. Quiet, sparse material compresses more; loud, dense masters compress less. Details of the format are published by the Xiph.Org FLAC project.
- MP3 is lossy and set by bit rate, so its size is fixed regardless of the content: bit rate × seconds ÷ 8. At 320 kbps that is 2.4 MB per minute; at 128 kbps, 0.96 MB per minute.
Worked example: a full session
Imagine a 4-minute song recorded at 48 kHz / 24-bit with 24 mono tracks. Each mono track is 8.64 MB per minute, so 24 tracks for 4 minutes is 24 × 8.64 × 4 ≈ 829 MB of raw audio, before any extra takes, comps or bounces. Record three takes of everything and the session passes 2.4 GB. A stereo master of the same song at 44.1 kHz / 16-bit is about 42 MB, a FLAC of it roughly 21–25 MB, and a 320 kbps MP3 about 9.6 MB.
Use the calculator to plug in your own session: choose a sample rate from 44.1 to 192 kHz, a bit depth of 16, 24 or 32-bit float, mono or stereo, and the length. It shows the size per minute, the total and the bit rate, with FLAC and MP3 estimates next to it.
MB vs MiB: why Windows shows a smaller number
A megabyte (MB) is 1,000,000 bytes; a mebibyte (MiB) is 1,048,576 bytes. Windows uses MiB but labels it “MB”, so the same file looks about 5% smaller there than on macOS or in the calculator. One minute of CD audio is 10.58 MB, which Windows shows as 10.09.
Why file size matters for musicians
- Drive space. Multitrack sessions at high sample rates fill drives quickly. Plan storage and backups before a big recording day. Our guide on how to back up audio files covers the backup side.
- Upload limits. Email attachments, some sharing links and some distribution or contest platforms cap file sizes. Knowing the size in advance tells you whether to send a WAV, a FLAC or a link.
- Mastering deliveries. Send mix files for mastering as WAV or AIFF at the session’s sample rate and bit depth, not as MP3. Our track preparation guide lists what to send.
- Streaming and transfer. Bit rate tells you how much data playback uses and how long a transfer takes.
Does a higher sample rate sound better?
Higher sample rates capture higher frequencies and can help some processing, but they also multiply file size and CPU load. Many producers work at 44.1 or 48 kHz with 24-bit depth for a good balance. Bit depth mostly affects noise floor and headroom while recording; 24-bit gives plenty of room for home and project studios. Choose settings for your workflow, then let the calculator tell you what it will cost in space.
How to keep session sizes under control
- Record mono sources as mono. A vocal, a bass DI or a single guitar mic does not need a stereo track, and recording it in stereo doubles the file for no benefit.
- Clean up unused takes. Most DAWs can list or remove audio files that are no longer used in the arrangement. Back up first, then tidy.
- Archive finished projects as FLAC. Lossless compression saves space on long-term storage without losing quality, as long as your DAW or converter can turn it back into WAV.
- Bounce heavy virtual instruments only when needed. Printing every synth to audio adds files; keep MIDI where it is light enough to run live.
Common mistakes
- Forgetting channels. Stereo is twice the size of mono at the same settings.
- Sending MP3s for mixing or mastering. Lossy files throw away information you cannot get back.
- Comparing MB and MiB. Different operating systems report sizes differently.
- Underestimating takes. Comps, alternate takes and bounces can multiply session size.
FAQ
How big is one minute of CD-quality audio?
44.1 kHz, 16-bit stereo is 10.58 MB per minute, at 1,411.2 kbps.
How big is a 24-bit 48 kHz stereo WAV?
About 17.28 MB per minute. At 96 kHz it doubles to about 34.56 MB per minute.
How much smaller is FLAC than WAV?
Usually around 50 to 60% of the WAV size, depending on the music.
How big is a 3-minute MP3?
At 320 kbps about 7.2 MB, and at 128 kbps about 2.9 MB.
Learn more about capturing clean audio in our recording guide. Planning a session or a delivery? Get exact numbers from the free audio file size calculator.