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Audio File Size Calculations
These calculations will help you to estimate the size of audio files.
NOTES:
1) "x" means "multiplied by". Forward slash (/) means "divided by".
2) Kbps means "Kilobits per second" (1,000 bits per second). KB means
KiloBytes (1,000 Bytes). There are 8 bits in a byte. Note the uppercase
"B" for bytes in "KB". A lowercase "b" (Kb) would indicate bits.
3) Calculations for MP3 files generally include both left and right stereo
channels. Calculations for PCM files must be multiplied by 2 to allow for
both left and right stereo channels.
4) We took reasonable care in computing these figures, but you may want to
doublecheck them if you're working on an important project. We did a
casual experiment with a one-minute PCM file, and Windows Explorer
reported it to be slightly smaller (10,337 KB) than what was predicted by
the calculations below (10,584 KB). This may be due to differences between
binary and decimal counting systems (multiples of 2 versus multiples of
10). In addition, file header information and ID3 tags (for MP3s) will
have an effect on the numbers. In general, however, we have have found the
figures below to be useful for approximating audio file sizes.
MP3 File Size Calculations
Formula:
Kbps = bits per second / 8 = Bytes per second x 60 seconds = Bytes per
minute x 60 minutes = Bytes per hour
Bitrate |
File size
per second |
File size
per minute |
File size
per hour |
8 Kbps |
1 KB |
60 KB |
3.6 MB |
16 Kbps |
2 KB |
120 KB |
7.2 MB |
32 Kbps |
4 KB |
240 KB |
14.4 MB |
40 Kbps |
5 KB |
300 KB |
18.0 MB |
48 Kbps |
6 KB |
360 KB |
21.6 MB |
56 Kbps |
7 KB |
420 KB |
25.2 MB |
64 Kbps |
8 KB |
480 KB |
28.8 MB |
80 Kbps |
10 KB |
600 KB |
36.0 MB |
96 Kbps |
12 KB |
720 KB |
43.2 MB |
112 Kbps |
14 KB |
840 KB |
50.4 MB |
128 Kbps |
16 KB |
960 KB |
57.6 MB |
160 Kbps |
20 KB |
1.20 MB |
72.0 MB |
192 Kbps |
24 KB |
1.44 MB |
86.4 MB |
224 Kbps |
28 KB |
1.68 MB |
100.8 MB |
256 Kbps |
32 KB |
1.92 MB |
115.2 MB |
320 Kbps |
40 KB |
2.40 MB |
144.0 MB |
PCM File Size Calculations
Here are some file size calculations for common PCM audio settings. PCM
stands for Pulse Code Modulation and commonly uses the file extensions
.wav or .cda. There are quite a few other combinations of bits per sample
and samples per second which may be used. We have included calculations
for the most common mono (one channel) and stereo (two channel) settings.
Mono
Formula:
Bits per sample x samples per second = bits per second / 8 = Bytes per
second x 60 seconds = Bytes per minute x 60 minutes = Bytes per hour of
mono.
Settings |
Bitrate |
File size
per second |
File size
per
minute |
File size
per
hour |
16 bit, 44.1
KHz |
705.6 Kbps |
88.2 KB |
5.292 MB |
317.52 MB |
16 bit, 48 KHz |
768 Kbps |
96 KB |
5.750 MB |
345.60 MB |
24 bit, 48KHz |
1,152 Kbps |
144 KB |
8.640 MB |
518.40 MB |
24 bit, 96KHz |
2,304 Kbps |
288 KB |
17.280 MB |
1.0368 GB |
Stereo
Formula:
Bits per sample x samples per second = bits per second x 2 channels = bits
per second of stereo / 8 = Bytes per second of stereo x 60 seconds = Bytes
per minute of stereo x 60 minutes = Bytes per hour of stereo.
Settings |
Bitrate |
File size
per second |
File size
per minute |
File size
per hour |
16 bit, 44.1 KHz |
1,411.2 Kbps |
176.4 KB |
10.584 MB |
635.04 MB |
16 bit, 48 KHz |
1,536 Kbps |
192 KB |
11.520 MB |
691.2 MB |
24 bit, 48KHz |
2,304 Kbps |
288 KB |
17.28 MB |
1.036 GB |
24 bit, 96KHz |
4,608 Kbps |
576 KB |
34.56 MB |
2.0736 GB |
Calculations
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