Bandwidth Calculator
Select the value you need, then enter the two known quantities. The overhead setting reduces the share of link capacity available to transfer your file.
Enter 0 when using measured payload throughput.
Estimated transfer duration
1m 20s
- Total seconds
- 80
- Minutes
- 1.333333
- Hours
- 0.022222
The connection is assumed to sustain its rate for the whole transfer. Upload and download speeds may differ.
Bits, bytes, and transfer time
Network speeds are commonly expressed in bits per second. File sizes use bytes, with eight bits in each byte. A 1 GB file contains 8 billion bits, so a steady 100 Mbps connection needs 80 seconds at zero overhead.
A GB represents one billion bytes; a GiB represents 1,073,741,824. Selecting the correct unit matters for large backups. MB/s is already measured in bytes per second, whereas Mbps measures bits. The unit menus apply these conversions before solving the transfer equation.
Allowing for a slower real transfer
If overhead is 10%, the model uses 90% of the entered link speed. That same 1 GB transfer takes about 88.89 seconds at 100 Mbps. To finish within 80 seconds under those conditions, the link would need roughly 111.11 Mbps.
The result assumes a constant rate for one transfer. Congestion can change throughout a download, and storage speed or the remote server may become the bottleneck. This is a planning estimate, not a speed test. For an observed payload rate, use that rate directly and leave overhead at zero to avoid counting the reduction twice.