Average rate vs peak rate
This calculator measures average throughput across the whole transfer. It can be much lower than a speed-test peak because of startup delay, congestion, storage speed, server limits or protocol overhead.
Example
Moving 5 GB in 420 seconds is about 95.2 Mbps, or roughly 11.9 MB/s. The Mbps figure is useful for network speed, while MB/s is often easier when comparing file-copy speeds.
Common mistakes
Bits and bytes differ by a factor of 8. Internet plans usually advertise megabits per second, while operating systems often show megabytes per second.
Limitations
The calculator reports an average. It does not diagnose packet loss, Wi-Fi signal quality, server throttling, disk speed or protocol overhead in detail.
Last reviewed: 2026-05-17