Practical AtlasIndependent referenceFree online tool
Bandwidth and download-time calculator
Convert file size and Mbps into a realistic download time, with the bits-to-bytes conversion and effective rate both written down.
Turn Mbps into time.
Compare the theoretical floor with an explicit effective-rate assumption.
COMMON WAYS TO ASK
- How long will this download take?
- Convert Mbps to MB per second
- Why is my download slower than my plan?
What this calculator tells you.
Convert a file size and a connection speed into a time estimate with the effective-rate assumption written down, because bits and bytes differ by eight and overhead takes the rest.
A 20 GB game on a 100 Mbps line
Questions people ask next.
Why is 100 Mbps not 100 MB per second?
Megabits and megabytes differ by a factor of eight, so 100 Mbps is about 12.5 MB per second before any overhead. That single confusion explains most disappointed download estimates.
What effective rate should I enter?
Use what you actually observe rather than the plan figure. Protocol overhead, the server, and everything else sharing the line mean sustained throughput is normally below the advertised rate.