Download time calculator
Connection speed is measured in megabits per second, file size in megabytes. A byte is eight bits, which is why a 100 Mbps line feels slow. The calculation handles the conversion.
Advertised speed is a ceiling, not a guarantee. Wi-Fi on 2.4 GHz, an old cable, the source server or a VPN can each cap the transfer far below what the line can do. Test with a cable straight into the router before complaining to the provider.
Frequently asked questions
Why isn't 100 Mbps equal to 100 MB/s?
Because a byte is eight bits. A 100 Mbps line moves at best 12.5 MB/s.
Why is my download slower than my speed test?
A speed test measures to a nearby optimised server. A real download also depends on the source server, on routing, and on how many devices share the network at that moment.
Is upload slower than download?
On asymmetric connections — coax, DSL, most mobile plans — yes, sometimes tenfold. On symmetric fibre, no.