Audio File Size Calculator
A 3-minute stereo recording at 44.1 kHz and 16 bit is 31,752,044 bytes as WAV (31.75 MB, 30.28 MiB, 44-byte header included). The same 3 minutes as 320 kbps MP3 is 7,200,000 bytes (7.20 MB).
How to use
- Pick the format. WAV is uncompressed PCM with a 44-byte header, and raw PCM has no header. FLAC is lossless but its size is only estimated. MP3, AAC and Opus are sized from their bitrate.
- Choose Size from length to get the file size, or Length from size to see how much audio fits in a given space.
- For WAV, PCM and FLAC set the sample rate, bit depth and channels. For MP3, AAC and Opus enter the bitrate in kbps.
- Enter the duration (hours, minutes, seconds), or the available space and its unit.
- Read the size in bytes, MB (decimal) and MiB (binary), or the recording time that fits.
How it works
Uncompressed PCM (WAV): bytes per second = sample rate x bit depth x channels / 8. File size = bytes per second x duration, plus a 44-byte header for a WAV file. CD audio (44,100 Hz, 16 bit, stereo) is 176,400 bytes per second, which is 1,411.2 kbps or about 10.6 MB per minute.
Compressed audio (MP3, AAC, Opus): file size = bitrate x duration / 8, with 1 kbps = 1,000 bits per second. A 320 kbps file uses 40,000 bytes per second, so 3 minutes is 7,200,000 bytes. This holds for constant bitrate. A variable bitrate file lands near its average bitrate, and container tags and cover art add a little.
FLAC is lossless, so its size depends on the music. Typical music shrinks to roughly 50 to 70 percent of the PCM size, and this tool shows that range with 60 percent as a midpoint. Silence compresses far more and noise barely at all, so treat FLAC results as an estimate.
Reverse mode divides the space by the bytes per second. Sizes are shown in MB (1,000,000 bytes, used by drive makers and most phones) and MiB (1,048,576 bytes, used by many operating systems), and a MiB is about 4.9 percent larger than a MB.
Size of 1 minute by format
| Format | Settings | Per minute |
|---|---|---|
| WAV / PCM | 44.1 kHz, 16 bit, stereo | 10.58 MB |
| WAV / PCM | 48 kHz, 24 bit, stereo | 17.28 MB |
| WAV / PCM | 96 kHz, 24 bit, stereo | 34.56 MB |
| FLAC (estimate) | 44.1 kHz, 16 bit, stereo | 5.3 to 7.4 MB |
| MP3 | 320 kbps | 2.40 MB |
| AAC | 256 kbps | 1.92 MB |
| MP3 | 128 kbps | 0.96 MB |
| Opus | 64 kbps | 0.48 MB |
FAQ
How big is one minute of CD quality audio?
About 10.58 MB (10.09 MiB) as WAV. CD quality is 44.1 kHz, 16 bit, stereo, which is 176,400 bytes per second.
Why is WAV 44 bytes bigger than the raw audio?
A standard PCM WAV file starts with a 44-byte header that stores the format, sample rate, channel count and data length. Some files carry extra metadata chunks, so the real size can be a bit larger.
How accurate is the FLAC figure?
It is an estimate. FLAC usually lands between 50 and 70 percent of the PCM size, but quiet or sparse recordings go lower and dense, noisy ones go higher. The only exact way is to encode the file.
What is the difference between MB and MiB?
A megabyte (MB) is 1,000,000 bytes and a mebibyte (MiB) is 1,048,576 bytes. Windows and some apps label MiB values as MB, which is why a file can look about 5 percent smaller there.
Does stereo double the size of an MP3?
Not by itself. MP3, AAC and Opus size comes from the bitrate you choose, whether the source is mono or stereo. For PCM and FLAC, stereo is twice the size of mono.