Data transfer time formula
The basic calculation is simple once data size and network speed use compatible units.
Transfer time (seconds) = data size (bytes) × 8 ÷ speed (bits/second)
Example: 100 GB at 1 Gbps
Using decimal units, 100 GB is 100,000,000,000 bytes. Multiply by 8 to get 800,000,000,000 bits, then divide by 1,000,000,000 bits per second. The ideal result is 800 seconds, or 13 minutes 20 seconds.
Common mistakes
Do not mix bits and bytes, and keep decimal GB/TB separate from binary GiB/TiB. Also remember that the formula gives an ideal baseline; real throughput can be lower.
Use the transfer calculator →