


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 oneminute 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

