Digital Media Data Units
Bits, bytes, and decimal or binary prefixes express different amounts of media data.
| Symbol | Meaning | Typical media use |
|---|---|---|
| b | bit | Network and media bitrate |
| B | byte: eight bits | File size and transfer amount |
| /s | per second | A rate rather than an amount |
To convert bits per second to bytes per second, divide by eight.
100 Mb/s ÷ 8 = 12.5 MB/s, before transmission overhead.
Look up the prefix
| Unit | Number of bytes |
|---|---|
| MB, megabyte | 1,000,000 |
| MiB, mebibyte | 1,048,576 |
| GB, gigabyte | 1,000,000,000 |
| GiB, gibibyte | 1,073,741,824 |
Decimal prefixes use powers of 1,000; binary prefixes use powers of 1,024. One billion bytes is 1 GB, or approximately 0.931 GiB. Both describe the same file length.
Convert a streaming rate into an amount
At an average of 8 Mb/s, the stream uses approximately 1 MB each second, or 60 MB each minute. For a longer interval, multiply the byte rate by the number of seconds. Bitrate and file size versus duration develop that calculation.