Download time calculator
Estimate how long a download or upload could take, with clear units and room for real-world overhead.
An estimate while the entered connection speed is available to this transfer.
No speed test runs and no file is uploaded. This is arithmetic using your inputs; server limits, Wi-Fi, other users and slow storage can make a transfer take longer.
Bits, bytes, and the wait in between.
Internet speeds are usually quoted in bits per second. File sizes are usually bytes. A byte is eight bits, so a 100 Mbps connection has an ideal transfer rate of 12.5 MB/s before other limits.
For a decimal 1 GB file at 100 Mbps, the ideal minimum is 80 seconds. At 80% efficiency, the same estimate becomes 100 seconds. The efficiency setting lets you explore an allowance rather than treating the advertised speed as a guarantee.
Use the speed that matters.
For a cloud backup, use your available upload speed. For a download, use the download speed available to this device and transfer. The other end of the connection may still be slower.
MB, GB and TB use decimal units here. GiB uses 1,073,741,824 bytes. This matters when a backup application reports a binary size.
Read the bits-versus-bytes guide or plan a first cloud backup.
A few useful answers
Why is my actual download slower?
The entered speed is only one constraint. Your Wi-Fi, router, destination server, storage, VPN, other traffic or transfer protocol may be the bottleneck.
Can I use this for an upload?
Yes. Enter the file size and the upload speed available to that transfer. Many home connections have very different upload and download speeds.
What does the default 85% mean?
It is an editable scenario. It is not a speed test, an industry average, or a guaranteed allowance. Try different values to see how much extra time a slower effective rate adds.