Media File Size Calculations
From MusicTechWiki
These calculations will help you to estimate the size of audio files.
Notes
- "X" means "multiplied by". Forward slash (/) means "divided by".
- 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.
- 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.
- We took reasonable care in computing these figures, but you may want to double-check 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 |
| 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 |