How Long Does It Take to Download 100 GB at 25 Mbps?
Downloading 100 GB at 25 Mbps takes about 9 hours 32 minutes under ideal conditions — expect roughly 11 hours 55 minutes to 19 hours 5 minutes in practice.
Why the real-world time is longer
A 100 GB file contains about 859 gigabits of data. At the full 25 Mbps line rate that transfers in 9 hours 32 minutes. Real download speeds, however, usually reach only 50–80% of the advertised rate because of protocol overhead, Wi-Fi conditions, network congestion, and limits on the other end of the connection — which is why a realistic estimate for this transfer is 11 hours 55 minutes to 19 hours 5 minutes. Press Calculate above to test your own numbers.