Download Time Calculator
Estimate download time from file size and speed. See seconds, minutes, hours, plus a realistic download ETA time you can plan around easily.
Download Time Calculator
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SIMILAR TOOLS
What this does
So you want to know how long a download will take, a game, a film, or a big backup, before you start it. This estimates it. Enter the file size and your download speed, each with its unit, and it works out the time, and even the clock time it should finish.
How to use it
- Enter the file size and pick its unit, from KB up to PB.
- Enter your download speed and pick its unit, such as Mbps or MB/s.
- Press Calculate to see the time and the estimated finish.
How it works
The calculation itself is simple, time equals size divided by speed, but there is one catch that trips almost everyone up, and the tool handles it for you. Once everything is in the same units, the time in seconds is just:
download time = file size ÷ download speed
The catch is the difference between bits and bytes. Internet speeds are usually quoted in megabits per second, written Mbps with a lower case b, while file sizes are in megabytes, written MB with a capital B. There are eight bits in a byte, so a connection's bit speed has to be divided by eight to compare it with a file's byte size:
bytes per second = bits per second ÷ 8
That is why a 100 Mbps connection downloads at about 12.5 MB per second, not 100. The tool knows which units are bits and which are bytes and converts correctly, so you can mix, say, a file in GB with a speed in Mbps and still get the right answer.
A realistic estimate
Treat the result as a best case. It assumes your connection runs at full speed for the whole download, which rarely happens in practice. Real speeds dip and recover, and there is some overhead along the way, so an actual download usually takes a little longer than the figure here. It is a solid number to plan around, not a stopwatch.
Questions people ask
Why is my download slower than this says?
The estimate assumes a constant full speed connection. In reality speed fluctuates and there is overhead, so real downloads usually take somewhat longer.
What is the difference between Mbps and MB/s?
Mbps is megabits per second, the usual way speeds are sold. MB/s is megabytes per second. There are eight bits in a byte, so you divide a bit speed by eight to get the byte speed.
Does it use 1000 or 1024 for units?
It uses 1000 based units, so a megabyte is one million bytes. That is the convention internet providers and storage sizes generally use.
Why does it show a finish time?
As a convenience. It adds the estimated duration to the current time so you can see roughly when the download should be done.
References
- Wikipedia. Data-rate units. https://en.wikipedia.org/wiki/Data-rate_units
Sugam Baskota is a senior software engineer and Computer Science graduate from UT Arlington, with interests in user scripts, browser extensions, developer tooling, and productivity systems. He spends time building practical utilities and extensions in the kinds of workflows Eon is designed to simplify. At Eon Tools, he reviews useful, password, and developer tools.