About the Download Time Calculator
How long a file takes to download at a given connection speed, allowing for real-world overhead.
Also known as: file download time, how long to download, transfer time calculator, upload-time.
How to use this calculator
- Enter file size, size unit, connection speed, speed unit and the other fields.
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Review the breakdown shown under the main result.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
time = file size ÷ (speed × (1 − overhead))
Worked example
Using the values pre-filled in the calculator above:
- File size = 5
- Size unit: GB
- Connection speed = 100
- Speed unit: Mbps (megabits/s)
- Protocol overhead = 10 %
the calculator returns:
- Download time: 7 min 24 s
- In seconds: 444.4
- Effective speed: 11.25 MB/s
- At full advertised speed: 6 min 40 s