Bandwidth & Data Rate Converter
Convert bit rates to byte rates (decimal 1000-based, with a strong Mb-vs-MB ×8 reminder) and estimate transfer time from file size and bandwidth.
>_ USAGE GUIDE
Bandwidth confusion is almost always about units: a "100M broadband" plan means 100 Mbps (bits per second) while your download client shows MB/s (bytes per second) — a factor of 8, so the real ceiling is 12.5 MB/s. This tool keeps the bit side (bps/Kbps/Mbps/Gbps/Tbps) and the byte side (B/s, KB/s, MB/s, GB/s) clearly separated, converts on the decimal 1000 scale, and estimates transfer time from a file size.
- Convert a rate: enter a value and pick source/target units; the main result is highlighted and every other unit is listed alongside
- Estimate transfer time: enter a file size (KB/MB/GB/TB) and a link rate to get the theoretical duration plus an 80%-effective-bandwidth correction
- Align on terms: the Mb ≠ MB reminder sits above the results — confirm both sides mean the same unit before sharing numbers
>_ FAQ
Q1 · Why 1000-based instead of 1024?
Network bandwidth has used the decimal SI scale since the telegraph era: 1 Kbps = 1000 bps. The 1024 scale belongs to binary bytes (KiB/MiB) in storage contexts. Networking conventions for both rates and file sizes use 1000, so dividing one by the other yields clean MB/s.
Q2 · Why does my 100 Mbps line only deliver about 10 MB/s?
The theoretical ceiling is 12.5 MB/s; after TCP/IP headers, handshakes and congestion control, real throughput typically lands at 80–90% of the link, and weak Wi-Fi or a throttling server lowers it further. The tool shows both the 100% figure and the 80% correction — compare against the 80% line first when troubleshooting.
Q3 · Are KB/s and kBps the same thing?
In this tool's convention, yes: both mean kilobytes per second (1000 B/s). The dangerous pair is capitalization: uppercase B = byte, lowercase b = bit, so MB/s and Mb/s differ by 8×. When a source is ambiguous, sanity-check the magnitude — home connections in the tens of "M" must be Mbps, since tens of MB/s would be multi-gigabit.
Q4 · Why is file size also 1000-based?
To keep the same scale as the rate, so the division introduces no hidden error. Operating system file managers may show 1024-based sizes (labeling MiB as MB); for precise estimates prefer the true byte count, though the ~2.4% gap rarely changes the conclusion.
Q5 · Why are uploads slower than the estimate?
The estimate assumes symmetric capacity. Most home connections have far less upload than download (for example 300 Mbps down / 30 Mbps up), so cloud backups must be estimated with the upload rate; TLS handshakes and acknowledgements trim it further — planning at 60–80% effective bandwidth is realistic.