Broadband speed explained

Do you want to know more about what your internet package could provide but need to have broadband speeds explained? We take a closer look at what broadband speeds are available and when you need them.

Written by

Matthew Brewer

Broadband and mobile expert

Last Updated

25 MAY 2023

9 min read

How are broadband speeds measured?

Internet speed measurement is done using Megabits per second (Mbps).

What is Mbps?

People often assume that a download speed of 1 Mbps will allow them to download a 1MB (Megabyte) file in one second. Unfortunately, this is not the case.

A Megabit is one-eighth the size of a Megabyte, meaning that to download a 1MB file in one second, you’d actually need a connection speed of 8 Mbps.

As broadband technology advances, you’ll see more and more mentions of gigabit-capable broadband. 1 Gigabit per second (Gbps) is equivalent to 1,000 Mbps. Now that’s fast.

Why do broadband speeds differ?

There are several reasons why broadband speeds vary from household to household and are sometimes slower than the advertised average speeds, including:

Where you live – if you live in towns and cities you’ll almost certainly have access to fibre broadband offering high broadband speeds. In some cases, ultrafast full fibre broadband with average download speeds of more than 900 Mbps, or even 1Gbps, are available, but it depends what connections there are to your home.

If you live in a rural area, the fibre roll-out may not have reached you yet. If so, you’re likely to be on copper wire systems, which are much slower and prone to service interruptions.
When you access the internet – when you use the internet can also impact speed. Accessing the internet at traditional peak times (a distinction that’s becoming a little blurred as more people work from home) could still lead to some temporary slowdowns in speed.

How much slowdown you suffer depends on the extent to which your provider has or hasn’t invested in its network.

You might want to avoid packages with traffic management, where download speeds are adjusted for particular activities at particular times, if you don’t want to be slowed down.

What is a good internet speed?

Superfast broadband is a commonly used term to describe an average internet speed of more than 30Mbps. This is a good download speed that’s widely available throughout the UK.

However, if your home has lots of people streaming music, TV and film, gaming online or downloading large files, you may need faster speeds to keep up with you all.

Download speeds vs upload speeds

When you compare broadband speeds, the download speed is normally the headline rate you’ll see advertised. Pretty much everything we do online involves downloading data, whether it’s streaming music, watching Netflix, playing online games, browsing the web or scrolling through social media.

A faster download speed means a better experience. For many of us, that means looking for a download speed that can handle our household’s online entertainment, work and study needs without slowing down.

Although we need to upload data all the time too, to post social media, make video calls, send emails, log into online banking or back up our data on the cloud, the quantities of data we upload are typically less. That’s why advertised upload speeds tend to be considerably lower. Broadband providers know that the typical user uploads less than they download so they configure their network to prioritise downloading data.

Can I complain to my provider about broadband speeds?

Yes. Your internet provider is required by regulatory body Ofcom to investigate any complaints you make about broadband speed. If it’s much slower than what they estimated it would be when you signed up, you’re well within your rights to request an affordable and decent connection.

If you think there’s a problem, it’s a good idea to record the broadband speeds you’re receiving, to back up your complaint. If your internet provider is unable to provide the speeds you were promised when you signed up to the deal within 30 days, they should allow you to leave your contract early without charging you an early exit fee.

You can check your internet speed against the speed of other providers in your area using our broadband speed test tool. If you’re not getting what you were promised and can find a better deal elsewhere, it could be a good time to switch broadband providers.

Under Ofcom rules, broadband providers must provide clear and transparent information about broadband speeds. This includes a minimum guaranteed speed and realistic broadband speed estimates for peak times.

What broadband speed do I need?

What speed you need depends on how you use the internet.

If you only use it for browsing the internet, you’ll need less speed than someone who uses the internet for streaming movies or online gaming.

A high-speed connection could give you significant benefits, particularly if:

You’re a family with several users using multiple devices
You can’t tolerate any ‘buffering’ interruptions when streaming TV shows or movies in Ultra HD, or making video calls
You enjoy gaming – not only will the faster download speeds help, but enhanced upload speeds allow near-instant responses and no lagging
Multiple people in your household work from home and regularly make video calls at the same time.

But bear in mind that you only need up to 5 Mbps to stream BBC iPlayer in HD, while 1.5 Mbps is the minimum recommended speed for the platform. Downloading a one-hour HD TV episode would take around a quarter of an hour if your broadband download speed is 10 Mbps.

The minimum recommended broadband speed for Netflix is 1 Mbps although you’ll need a faster speed to get decent video quality. For high-definition viewing, Netflix recommends a minimum speed of 5 Mbps or 15 Mbps for Ultra HD. If your download speed is 30Mbps, that one-hour HD TV episode should take under four and a half minutes to download.

Find out which type of broadband you need to suit your streaming requirements.

How can I check my broadband speed?

You can check your broadband speed with our broadband speed checker.

It’s free, simple to use and you can compare your connection speeds to your neighbours’ average internet speeds, and see your options if you’re keen to switch providers.

You should make sure that nobody else is using the internet at the same time and, if possible, use a wired connection using an ethernet cable to ensure you get an accurate result.

Speeds fluctuate throughout the day so you might want to consider running the test a couple of times.

Are fibre broadband speeds always faster?

Fibre broadband is faster and more reliable than ADSL (asymmetric digital subscriber line) broadband because of the technology it uses.

An ADSL connection uses copper wires and electrical signals to transfer data, while a fibre connection uses light. That means your downloads and uploads travel much faster.

However, the speed and quality of your fibre broadband will vary according to your provider and where you live.

What broadband speed can I get?

The broadband speeds you can access depend largely on where you live. To find out which speeds you have access to, simply use our broadband comparison service.

Compare broadband speeds in your area

Frequently asked questions

What is the broadband Universal Service Obligation (USO)?

The broadband Universal Service Obligation means that every home and business in the UK has a legal right to a decent and affordable broadband connection.

Under this legislation, eligible UK homeowners can ask BT (or KCOM for Hull residents) to upgrade their broadband connection if they get download speeds of less than 10 Mbps and upload speeds of less than 1 Mbps. So long as your share of the cost of upgrading the local network is less than £3,400, you won’t have to pay a penny. If it costs more, you’ll be quoted a price for the excess costs.

Under USO you could also request a connection upgrade if you’re only able to access broadband services that cost over £48.90 per month.

What are the peak times when my broadband speed is likely to be slower?

Ofcom defines peak times for internet use as between 8-10pm.

This could be when everyone is most likely to be at home and using the internet for activities that need greater quantities of data, such as streaming TV or gaming.

What do average speeds mean when comparing broadband deals?

According to rules set by the Advertising Standards Authority (ASA), the broadband speed that a broadband provider advertises must be the average speed that at least 50% of their customers receive at the network’s busiest time (8-10pm).

You could make a complaint to the ASA if you believe that a broadband provider is falsely advertising faster download speeds.

Do wired connections have faster broadband speeds than wireless connections?

Wired connections that use an ethernet cable to transfer data can be faster and more reliable than wireless connections.

WiFi signals could be interrupted by other nearby devices and the strength and speed of your connection will be affected by factors like how far away the device you’re using is from the router.

That being said, there are definitely disadvantages of having a vast network of ethernet cables running around your house. If you want to maximise your home broadband speeds, you may want to run an ethernet cable to your TV or games console for particularly data-heavy activities like streaming video and online gaming.

How are fair usage policies related to broadband speeds?

Because most customers share internet connections, some broadband providers have fair usage policies in place to stop data-hungry neighbours from slowing down everyone else’s connection.

They do this by imposing a cap on heavier users in peak times, so they can’t take more than their fair share. This could be frustrating for customers who have chosen unlimited broadband deals because of their household data needs, so it’s important to check for any fair usage policies when you compare deals.