Download Time Calculator

Enter a file size and your connection speed to see how long a download should take. The calculator shows two numbers: the theoretical best case, and a realistic estimate that allows for the overhead every real download has.

Don't know your speed? Run the speed test first and use the download number it shows. It takes about ten seconds.

How the calculation works

Storage is measured in bytes and internet speed in bits. One byte is eight bits, and that factor of eight explains most of the confusion about download times. A 100 Mbps connection moves 100 million bits per second, which is 12.5 million bytes, or 12.5 MB per second.

So the best-case time is: file size in bytes × 8 ÷ speed in bits per second. A 100 GB game on a 100 Mbps line is 800 billion bits divided by 100 million bits per second, which is 8,000 seconds, or 2 hours 13 minutes.

File sizes here use decimal units (1 GB = 1,000,000,000 bytes), the same way game stores and internet providers count. Windows shows sizes in binary units, so a file Windows calls “93 GB” is about 100 GB in store terms.

Why real downloads take longer

The realistic estimate adds 15% to the best case. That is a typical allowance, not a fixed rule. It covers:

• Protocol overhead. Every packet carries addressing and error-checking data that isn't part of your file, usually a few percent.
• Wi-Fi losses. A device a couple of rooms from the router can see half the speed the line delivers, or less. Our Wi-Fi vs Ethernet guide shows how much.
• The server's limit. A download can only go as fast as the far end sends it. On a busy launch day, a game store's servers are often the bottleneck, not your line.
• Everyone else at home. Streams, calls and background updates share the same connection.
• Disk speed. Consoles and PCs unpack large games while downloading, which can slow the final stretch on older drives.

If your real download is much slower than the estimate, more than about twice as long, the cause is usually one of the last three, not your plan.

Common download times

Best-case times, rounded. Add around 15% for a realistic figure.

File	50 Mbps	300 Mbps	1 Gbps
4 GB HD movie	11 min	2 min	32 sec
25 GB 4K film	67 min	11 min	3 min 20 s
100 GB game	4 h 27 min	44 min	13 min
200 GB game	8 h 53 min	1 h 29 min	27 min
1 TB backup	44 h 27 min	7 h 24 min	2 h 13 min

How to make a big download finish sooner

• Use a cable for the device that is downloading. It is the single biggest improvement for most homes.
• Pre-load when you can. Large games often allow downloading days before release. Starting early matters more than any setting.
• Download overnight. Evening is peak time for both your provider and the store's servers.
• Pause other big transfers. Cloud backups and system updates compete for the same line.
• Leave the console in rest mode with downloads allowed instead of switching it fully off.

Uploads work the same way, only slower

Uploading a file follows the same arithmetic using your upload speed. On most cable and DSL plans upload is a fraction of download, so a video that downloads in minutes can take an hour to upload. Our guide on why upload is slower explains why.