File Transfer Time Calculator
Enter a file size and a connection speed to estimate how long a download, upload or backup will take.
How it works
Network speeds are quoted in bits per second (Mbps) while file sizes are in bytes; one byte is 8 bits, so a 100 Mbps link moves at most 12.5 MB per second. Real transfers lose some capacity to protocol overhead, retransmissions and the remote server, so an overhead of 5-10% is a sensible estimate.
Sizes use decimal units (1 GB = 1,000 MB), as used by network and storage vendors.
Frequently asked questions
Why is my download slower than my plan's speed?
Overhead, Wi-Fi quality, the server's own limits and congestion all reduce real throughput below the advertised speed.
What is the difference between Mbps and MB/s?
Mbps is megabits per second; MB/s is megabytes per second. Divide Mbps by 8 to get MB/s.
How long does 1 TB take on gigabit?
Around 2.5 hours at full line rate (1 Gbps), longer with overhead.