GB vs GiB, Mbps vs MB/s
Storage capacity and network speed use similar letters for different quantities. UnitTidy keeps these meanings explicit.
SI and binary prefixes
| Unit | Definition |
|---|---|
| 1 kB | 1000 B |
| 1 KiB | 1024 B |
| 1 MB | 1,000,000 B |
| 1 MiB | 1,048,576 B |
| 1 GB | 1,000,000,000 B |
| 1 GiB | 1,073,741,824 B |
SI prefixes use powers of 1000. Binary prefixes such as Ki, Mi and Gi use powers of 1024. In this tool, GB always means decimal and GiB always means binary. A vendor or operating system may use labels differently; check the original source's definition.
Bits are not bytes
One byte (B) contains eight bits (bit). Mbit/s is also commonly written Mbps. A 100 Mbit/s connection therefore corresponds to 12.5 MB/s at full efficiency. It does not imply that every download will sustain that rate.
Estimate download time
Convert the file size and transfer rate to the same byte system, then divide size by effective bytes per second. Efficiency is a user-supplied assumption, not a measured network property. Multiple concurrent transfers, latency, protocol overhead and disk performance can change the outcome.
Source: NIST: prefixes for binary multiples.