Download Time Calculator
How long will that download actually take?
Enter a file size and your connection speed to get a realistic download time. Handles the byte-vs-bit mismatch that makes real downloads slower than the advertised Mbps, with an adjustable real-world efficiency factor.
Estimated time
Recommendations are planning estimates, not electrical or purchasing advice. The hardware figures behind them are vendor-published; your exact board-partner model and build can still differ.
At your efficiency
37m 2s
What you'll realistically wait.
Theoretical best
2000 s
At 100% of the line rate.
Effective throughput: 12.5 MB/s at 100% — remember your speed is in bits and the file is in bytes (8 bits per byte).
Methodology — Recommendations are planning estimates, not electrical or purchasing advice. The hardware figures behind them are vendor-published; your exact board-partner model and build can still differ.
Frequently asked questions
Why is my download slower than my Mbps plan suggests?
File sizes are quoted in bytes (MB, GB) but connection speeds are quoted in bits (Mbps). There are 8 bits in a byte, so a 100 Mbps line moves about 12.5 megabytes per second, not 100. On top of that, real transfers rarely hit 100% of the line rate — this tool lets you set a realistic efficiency factor.
What efficiency factor should I use?
For a wired connection to a fast server, 90–95% is realistic. Over Wi-Fi, a congested network, or a slow server, real throughput can be far lower. The calculator defaults to 90%; set it to 100% to see the theoretical best case.
Does this use decimal or binary units?
Decimal (SI) units, matching how ISPs and drive makers label things: 1 MB = 1,000,000 bytes and 1 Mbps = 1,000,000 bits per second. Operating systems sometimes report binary units (1 MiB = 1,048,576 bytes), which is a separate ~5% difference.