This download time calculator will help you determine the time it will take to download a file at a given internet bandwidth. An internet bandwidth provides information about a network's upload and download speed, and the faster the internet download speed is, the faster we obtain the file or data we need. Keep on reading to learn how long to download, let's say, your favorite video clip.

Understanding computer file sizes

Computer file sizes vary depending on the amount of data or information a computer file stores. When storing data, computers use what is called bits, an abbreviation of "binary digits." A bit can save either a yes or a no, black or white, and so on. Data stored in bits are represented by 1's and 0's and can be combined with other bits to form useful files like texts, images, audio, or videos.

Storing more bits together means that more information is present in the file. Grouping 8 bits together forms what is called a byte. A single symbol or letter in a text file takes up approximately 1 byte of computer storage. Like any other unit of measurement, when we talk about large amounts of something, we can use prefixes to quickly show the scale we are dealing with. Trust us, this is much better than using a huge number and the same unit of measurement. In file sizes, we also use a set of prefixes to express large amounts of data, and you can see these prefixes in the table below.

Byte Conversion Chart (SI Prefixes)
8 bits 1 byte (B)
1000 bytes 1 kilobyte (KB)
1000 kilobytes 1 megabyte (MB)
1000 megabytes 1 gigabyte (GB)
1000 gigabytes 1 terabyte (TB)
1000 terabytes 1 petabyte (PB)
1000 petabytes 1 exabyte (EB)
1000 exabytes 1 zettabyte (ZB)
1000 zettabytes 1 yottabyte (YB)

As shown in the chart above, we can express a thousand bytes as one kilobyte, 1000 kilobytes as one megabyte, and so on, just like in SI units. However, for a very long time, this conversion does not hold. Since data measurement follows the binary system, which uses powers of 2, a kilobyte used to be equivalent to 210 bytes or 1,024 bytes. On the other hand, a megabyte is equal to 1,024 kilobytes, and so on. Nowadays, we commonly use 1,000 (or the SI conversion) instead of 1,024 (binary conversion) to convert these units. However, new prefixes have been developed for binary conversion in case we need to use them. These prefixes are shown in the table below.

Byte Conversion Chart (Binary Prefixes)
8 bits 1 byte (B)
1024 bytes 1 kibibyte (KiB)
1024 kibibytes 1 mebibyte (MiB)
1024 mebibytes 1 gibibyte (GiB)
1024 gibibytes 1 tebibyte (TiB)
1024 tebibytes 1 pebibyte (PiB)
1024 pebibytes 1 exbibyte (EiB)
1024 exbibytes 1 zebibyte (ZiB)
1024 zebibytes 1 yobibyte (YiB)

You can also learn more about this in the "What is the difference between Mb and Mib" section of our video file size calculator.

Why we download computer files

Files cannot always be in just one computer or machine. When we take a picture using a digital camera, we need to have a way to transfer the picture file to a computer and then to a printer to end up with the image printed on a piece of paper. With that said, several ways have been developed for us to be able to transfer digital files from one device to another. The simplest way to transfer a file is through a data cable specifically made to transmit data.

Nowadays, we can also transfer data wirelessly through radio frequencies like Bluetooth or Wi-Fi. We can now also upload or transfer data to the internet so that other people can access it. The internet is a series of computer networks running all across the world. With the internet, we can now easily send any file to our loved ones, even if they are a thousand miles away from us, as long as they also have access to the internet. All we need to do is upload our file to the internet. Then, to access our file, people have to download it to their devices.

Upload and download speeds

Uploading and downloading data can take a while, depending on the file's size and transfer rate. Think of it like pouring water into a beaker. Pouring water from one beaker to another will only take a little amount of time. However, if we place a funnel on one beaker, the amount of water flow will decrease due to the narrow part of the funnel.

The flow rate of the water in this analogy is similar to the transfer rate of a file. We can compare a funnel's narrow tube part to what is called the internet's bandwidth. The larger the bandwidth is, the more data that can be transmitted at a time. Therefore, a file can be transferred much faster if the internet connection has a larger bandwidth.

Bandwidth is also, in a way, an internet connection's maximum capacity, and we can express it in units of bits per second. Internet bandwidth can also represent the maximum speed an internet connection can have. However, when moving a file from one computer to another, the maximum transfer speed will depend on the slowest bandwidth that the data has to go through - which can be anywhere in the route.

To better understand this, let us consider an example. Let's say that your friend wants to send you his new 400 MB (megabytes) video creation over his 10 Mbps (megabits per second) internet connection. On the other hand, you will be receiving the video file over your 5 Mbps home internet connection. For this example, let us assume that the upload and download speeds for both connections can use their entire bandwidths. Since the file will also be coming through the much lower 5 Mbps connection, this will be the maximum transfer speed that we can get for this data transfer. But, to determine the upload and download speeds of your connection, you can use any third-party speed test applications that can be accessed online through your browser.

How to determine download time

Now that we know how to determine the transfer speed for our uploads and downloads, we can now calculate a file's download time or duration. Calculating download time is as simple as dividing the size of the file you wish to transfer by the transfer speed of the network that the transfer will go through. However, we have to be careful with the units we use, since this could be quite confusing.

Let us consider the example above for our sample computation. To calculate how long to download the 400 MB video over a 5 Mbps internet download speed, we can use the equation below:

download time = file size / internet download speed

But first, let us convert the units of the file size in terms of megabits, which is equivalent to 1 million bits. To do so, we'll be using the conversion table above under the SI system. With that said, we now have this computation:

400MB in bits = 400MB * (8 bits / 1 byte) * (1,000 bytes / 1 kilobyte) * (1,000 kilobytes / 1 megabyte)

400MB in bits = 3,200,000,000 bits

400MB in megabits = 3,200 megabits (Mb)

Now, to calculate the download time, we have the to do the following computation:

download time = 3,200 Mb / 5 Mbps

download time = 640 seconds =10 minutes and 40 seconds

As shown above, the 400 MB video file will finish downloading in less than 11 minutes over a stable 5 Mbps connection. However, if somebody else in the house uses the internet while you're downloading this video file, it could take much longer to complete the download because of congestion in the data transfer.

Aside from calculating the download time of a file from the internet, you can also use this calculator to determine the transfer duration from, let's say, a computer to an external storage device like a USB flash drive. However, you must first know the transfer rate of your connection to calculate the transfer duration. You can also use this download time calculator to determine your download speed. However, for this, you have to time how long to download a particular file. Then, by entering the file size and the download time in our calculator, you'll be able to calculate your internet's download speed.

Download completion time

If you want to determine the actual time your download will take to complete, you can input the estimated download time into our time duration calculator. Our time duration calculator will help you determine the actual completion time of the download.

Kenneth Alambra