How to use this tool
Enter file size with the correct byte-based unit and connection speed in megabits per second.
Set usable throughput to allow for your assumed overhead. Actual congestion and connection behavior can change the duration.
Seconds = file bytes × 8 / (Mbps × 10⁶ × usable fraction)
Worked example
0:01:29 · estimated transfer duration
Fixed example using the settings below. Monetary examples use USD; dates and times use their stated reference values. This example stays unchanged when you edit your calculation.
Example inputs
- File size: 1
- File size unit: GB (10⁹ bytes)
- Connection speed (megabits/second): 100
- Usable throughput (%): 90
Method illustration: 1 GB over 100 Mbps takes 80 seconds at 100% usable throughput.
Assumptions and limits
- Connection speeds are bits per second, file sizes are bytes. Throughput accounts for your assumed overhead; actual congestion can vary.
Check or report a result
Check the units, selected calculation and assumptions first. Compare the fixed example above with your inputs to identify what changed.
Report a calculation issue with the page address, hypothetical inputs, result displayed and result expected. Do not include passwords, bank details or other private information.