So if you were downloading an HD movie with a 1500MB (1.5GB) file size, it should finish downloading in about five minutes. When you see an internet speed of 40Mbps, that means about 5MB (one-eighth of that) will be transferred each second. Learn more about the difference between bits and bytes with our dedicated guide.

A ‘bit’ is eight times smaller than a ‘byte’. ‘Gigabytes’ (GB) and ‘Terabytes’ (TB) are other common examples. You may have heard of ‘megabytes’ (MB) before - this is the format used to describe how large a computer file or programme is.

It refers to how many ‘megabits’ of data can be transferred to or from your device every second. ‘Mbps’ stands for ‘megabits per second’ - it’s the most common measurement used for broadband speeds. But what does that actually allow you to do? How fast can you download movies, albums or files? Let’s suppose you’ve tested your broadband and you’ve got a speed of 40Mbps. back to top How does the Uswitch broadband speed checker work? If you run a Wi-Fi speed test and find that your postcode can get much faster internet speeds, you might be able to improve your connection for a slightly - and very reasonably - higher monthly cost. You can also use the results to compare your broadband speed with other broadband deals that are available in your area. However, the results can come in useful if you’re complaining to your provider about your speed, thanks to Ofcom’s Voluntary Code of Practice on Broadband Speed which sets out a minimum continuous speed providers have to supply. Your first results should not be seen as a full measure of your broadband’s overall performance, so you might want to test it a few times at different points in the day to get a better overall reading. We’re always updating our broadband speed checker to be as accurate as possible, but you should know that the speed test results only represent a snapshot of your broadband connection at the time of testing. It can measure speeds for all types of broadband, including copper ADSL, fibre-optic, cable and mobile broadband, plus your mobile data speed if you’re out and about. The Uswitch Broadband Speed Test is a free service that tells you your current internet speed in seconds.

Broadband broadband download speed test