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Download Time Calculator
Work out how long a download takes at your internet speed, or the speed you need to finish it in time.
About Download Time
A download time calculator works out how long a file takes to transfer at a given internet speed. Enter the file size and your speed, and it shows the time at once, plus a table for common sizes and the speed you would need to finish within a minute, ten minutes or an hour. It handles both decimal units (MB, GB, TB) and the binary units Windows uses (MiB, GiB), and megabits or megabytes per second. Run our speed test first and it hands its result to this page, so the answer uses your real speed.
How download time is calculated
Time in seconds equals the file size in bits divided by the speed in bits per second. A byte is 8 bits, so a 10 GB file is 80,000 megabits, and at 100 Mbps it takes 800 seconds, a little over 13 minutes.
MB or MiB, GB or GiB?
| Unit | Bytes | Prefix |
|---|---|---|
| 1 MB (megabyte) | 1,000,000 | Decimal, 10 to the power 6 |
| 1 MiB (mebibyte) | 1,048,576 | Binary, 2 to the power 20 |
| 1 GB (gigabyte) | 1,000,000,000 | Decimal, 10 to the power 9 |
| 1 GiB (gibibyte) | 1,073,741,824 | Binary, 2 to the power 30 |
NIST defines the binary prefixes kibi, mebi and gibi as powers of 2, separate from the decimal kilo, mega and giga. Some software labels binary sizes with the decimal names, so a size shown as "4 GB" may really be 4 GiB, about 4.29 billion bytes. Pick the unit that matches where you read the size.
Speeds: Mbps and MB/s
Internet plans and our speed test use megabits per second. Browsers and game launchers often show megabytes per second, which is eight times smaller for the same connection. Our guide to what a good internet speed is explains how much speed different households need.
Source: NIST, prefixes for binary multiples.
Frequently asked questions
How long does it take to download 1 GB at 100 Mbps?
About 80 seconds. One gigabyte is 8,000 megabits, and 8,000 divided by 100 Mbps is 80 seconds. In practice expect a little longer, because protocol overhead, the server and Wi-Fi all take a share.
How do I convert Mbps to MB/s?
Divide by 8. Internet speeds are quoted in megabits per second (Mbps) and download managers usually show megabytes per second (MB/s). A 100 Mbps connection downloads at up to 12.5 MB/s.
What speed do I need to download 100 GB in an hour?
About 222 Mbps. 100 GB is 800,000 megabits, and 800,000 divided by 3,600 seconds is 222 Mbps. The table under the result shows the speed needed for any size and deadline you enter.
Why is my download slower than the calculator says?
The calculator assumes your full line speed for the whole transfer. Real downloads lose some of it to protocol overhead and other devices on the network, and the server may send more slowly than your line can receive. Run our speed test to measure what your connection actually delivers.