Broadband Speeds Explained

  • Learn more about how your broadband works
  • How your type of connection limits your max speeds
  • How much speed you need for certain common tasks
  • How slow internet access may not be down to your provider

Broadband Speeds Explained

Broadband speed is the single biggest factor cited by most internet users in terms of what influences their choice of provider and package, as well as in determining how happy they are with their current provider – so why is it so important? Put simply, the faster your broadband, the more you can do with it – and the fewer limitations and interruptions you can expect while using it. When looking at connection speeds offered by various providers, you’ll often see two figures quoted – one for ‘download (or downstream) speed and one for ‘upload’ (or upstream) speed. Read on to find out how speed is measured, what these two figures represent, how they affect you and why. While we’ve tried to explain as clearly as possible, you may find our Glossary of Broadband Terms useful if you’re unfamiliar with any of the terminology that we’ve used.


How is broadband speed measured?

Broadband speed is measure in terms of the maximum amount of data that can be transferred per second. Put simply, the higher that number, the more data you can transfer and the faster your connection is.

The units used for speed measurement where broadband is concerned are Megabits per second, or Mbps.

Some users may be familiar with Kilobits per second (Kbps) being used to explain speeds but these relate to older, far slower internet connections and are not really helpful any more – although it does illustrate just how much faster connection have become over time when you consider that 1 Mbps = 1000 Kbps.

To put that in context, before the first ADSL broadband was launched by BT in 2000, 56Kbps was the fastest internet connection speed over a standard phone line! That would equate to a mere 0.056 Mbps, which is a tiny fraction of the speeds available from even the slowest and most antiquated broadband available today. ADSL when it first launched ran at 512 Kbps, or 0.512 Mbps.


What are upload and download (upstream / downstream) speeds and how do they affect me?

Download, or downstream speed refers to the speed of data transfer being sent to your device from the internet, whereas upload or upstream speed is the speed of data being sent from your device to the internet.

Examples of activities that would constitute downloading would be streaming a song from Spotify, streaming a film from Netflix, browsing the internet or flicking through your friends latest exploits on social media. Basically anything where you’re primarily consuming content that isn’t your own.

Uploading would be activities such as posting videos to Facebook or adding pictures to Instagram, backing up your device to ‘the cloud’, sending emails with large attachments, using IP-based home security cameras that can be viewed from internet – or any situation where you are pushing information away from your end of the connection towards the internet.

Since most users consume far more data than they upload, download speeds are typically far higher (around 10x on average) than uploads speeds on a given connection.

(This where the ‘A’ in ADSL comes from – the lop-sided, downstream-biased nature of the connection is described as being ‘asymmetric’. The opposite of this would be ‘symmetric’ – synchronous broadband would have similar upload and download speed capabilities. SDSL does exist, but not really within the consumer internet connectivity market.)

The asymmetric nature of most broadband connections works very well for the vast majority of people and the only people who would normally find their upstream speed to be a significant factor would be those creating a lot of rich content that needs to be uploaded to the internet, such as HD video and other media-rich applications. For everyone else – download speed is far more important.


What factors affect the speed of my internet connection?

A multitude of factors affect the speed of your connection and most of them probably wouldn’t even cross your mind:

1. Line quality and interference:

Where your broadband is provided over your phone line, always make sure that your router is connected to the master socket – the socket where your phone line enters your property. If you’re not sure which is your master socket, you can usually figure this out from outside your property by following the external cabling back to a BT pole or box. Make sure that microfilters are connected to all extensions to ensure that you block any interference between the broadband and phone devices using the same line.

Occasionally, line faults can weaken your broadband signal or disrupt it entirely – often after particularly bad weather. If you believe this to be the case you will need to report any slowdown or outage to your provider once you’ve carried out basic checks such as checking all cables are secure, rebooting your device and rebooting your router.

2. Your broadband router:

If you have an older router and are using the built-in wifi, then chances are that it isn’t capable of supplying data to wireless devices very quickly or particularly efficiently, and nowhere near as quickly or efficiently as most modern smartphones, laptops and tablets can handle. There are 2 main ways in which this will become apparent – poor wireless range and poor wireless speeds – often both. If you’ve been on the same package for a long time then perhaps look at a new package with your existing provider or a different one – it’s likely that it’ll come with more up-to-date and more capable router hardware.

If you’re using a provider-supplied router and you pay the lowest possible price for your broadband, then you can expect your provider to choose their router hardware accordingly. There’s absolutely nothing wrong with making savings, but understand that in order to provide a cut-price broadband package, your provider is going to do the same thing at their end to make a profit. There’s always a degree of truth in the phrase ‘you get what you pay for’ – although that doesn’t mean that good value deals with decent hardware are not possible.

3. Your home network components:

If your router or a network switch on your home network is old or of poor specification it may struggle with processing the amount of data flowing through it. If you have an older 100 Mbps Ethernet network switch on your network and 300 Mbps broadband, then the maximum connection speed to your device is 100 Mbps – or only as fast as the slowest component in the chain. Likewise, old cables that have been kicked around and trodden on are not going to give you the best or most reliable connections.

4. The age, condition and specifications of the devices you’re using to access the internet.

A 5 year old tablet that’s running out of storage space and which supports 5-10 year old wireless standards isn’t going to give you the same performance as a newer device that is capable of taking advantage of the latest standards. Connection aside, it’s going to be inherently slower as it will struggle to process the amount of data that you’re expecting it to handle from today’s media-heavy applications.

Likewise, it’s going to be pointless connecting an ageing, neglected family PC that’s likely full of malware to a 300 Mbps fibre connection. You’d probably be better off with a new computer and a slower connection overall!

Many users who move to newer devices are amazed at the performance difference – this is due to a combination of factors; degraded performance of their old devices over time which has been gradual and therefore largely unnoticed, and the increase in performance of newer devices over that same period.

If you’re not in a position to upgrade your hardware then at least perform some basic housekeeping tasks on it – make sure your device is up to date, update your browser and ensure that you’re running anti-malware software and that you scan your device frequently.

5. Your connection infrastructure

Where you live, how far you are from the nearest exchange or cabinet and the type of technology your connection uses will all affect your connection to varying degrees. Even periods of extreme weather can adversely affect your broadband speed. Here’s how:


With a maximum possible downstream connection speed of 24 Mbps (although you’d pretty much have to be living next door to your nearest telephone exchange to get even close to that), the ADSL family of broadband options are provided over good old copper cables – the same ones carrying the traditional landline into homes for decades – and therein lies the problem. There’s only so much data you can push through a single pair of ageing copper cables – and this is made worse the further you get from the nearest BT exchange.

As you move further away from the exchange the signal loses strength (attenuation) and background interference and line noise reduce the maximum stable line speed that the router can sustain. Anything over 3 km or so away from your nearest exchange and you’re going to be lucky to see 10 Mbps. Double that and you can expect to see the speed halve again. Get to 5km from your local exchange and you’re looking at 2 Mbps if you’re lucky. This is why broadband has been a bit of a lottery for many rural users. The more remote your location, the worse your chances are.

On top of this, a significant proportion of the copper cable infrastructure is above-ground, leaving it open to the elements, accidents and vandalism of equipment.

Fibre-to-the-Cabinet, or ‘FTTC’:

Essentially a hybrid, and the most common form of fast and superfast broadband in the UK.

Your provider provides a fibre optic cable to the routing equipment in the nearest street cabinet, where it is then passed over your phone line or coaxial cable for the remaining very short journey to your home or business premises. The short distance of the non-fibre optic portion cuts out the majority of the issues associated with ADSL variants above, although the final run of cable from the cabinet to your home may still present issues if it’s legacy copper cabling and potentially decades old.

Fibre-to-the-Home, or ‘FFTH’:

This is the ideal type of connection – you are connected directly from your home to your provider via optic fibre and there are no weak-links in the chain of communication such as old copper cables, so there’s practically no opportunity for any kind of interference. Connections such as these offer the best possible speeds with the lowest amount of lag or latency, since you’re literally transferring data at lightspeed! Speeds of 1 Gbps (1000 Mbps) would be entirely and reliably deliverable over an FTTH infrastructure. At the time of writing, roughly only 2% of UK homes can get FTTH.

6. WiFi Configuration, Location, Range & Interference

If you are using a wireless connection between your router and your device, you may experience connection or speed problems from time to time. It is important to understand that wifi is essentially a radio signal and as such numerous things can interfere with it. To minimise the impact of this, always try to place your wireless router away from other electrical devices such as televisions (particular the older CRT type), cordless phones, dimmer switches, speakers, lamps and microwave ovens which can interfere with the wireless radio connection – as can many other electrical devices – Christmas fairy lights, particularly the flashing type, are an annual repeat offender in this respect!

In order to get the best possible coverage throughout your home it is essential to consider the location of the wireless router, although in most cases this is going to be limited by it needing to be connected to your phone socket or cable connection where it enters your property.

Most new routers are ‘dual band’, offering both 2.4GHz and 5GHz wifi connections simultaneously. If your device supports 5GHz it is worth using it as it supports far higher speeds than the 2.4GHz band and may also assist with your range issues.

If you’re still having wifi reliability issues, try speaking to your provider – they may talk you through changing the wireless channel on your router, which could solve problems caused by your wireless network being on the same channel as your neighbours – quite common in urban areas and easily resolved.

Finally, make sure you secure your wifi with a strong password to prevent others using it without your knowledge and slowing your connection down.

7. Do you really need wireless?

Generally speaking, if you’re using a desktop or laptop and can run a cable, run a cable.

A cabled connection to a desktop PC or Mac will always give you a faster and more reliable connection than wireless with current technologies. In the last few years, this has been made considerably easier by the widespread availability of powerline Ethernet adapters.

These clever devices are a pair of adapters that plug into your mains electricity sockets and pass data securely between them, using your home’s electrical cabling. You can add multiple additional extenders to the network to allow you to create a reliable, secure network throughout your property with minimal effort and no unsightly cables. They are more secure, more reliable and faster than the majority of wireless connections.

You can even buy versions of these with built-in wifi extenders, and this is an excellent way of improving wifi coverage in large properties or those with wifi blackspots.

8. Time of Day

Why does my connection seem to slow down in the evenings? Well, in the UK, peak internet usage is typically between 6pm and 11pm, with many users simultaneously streaming media through the likes of Netflix and Amazon Prime and other bandwidth-hungry apps, along with high levels of social media and web browsing activity. Depending on your provider, how many people in your area are sharing the same exchange and how heavily they are all using their own service, you may experience a slight slowdown of your own broadband connection during these times.

9. The number of other people and devices in your property and how they’re used

If your connection is being shared between multiple users then you will essentially be splitting the available speed between you. If you’ve got kids streaming from YouTube on their phones or tablets, you’re likely going to notice that your own activities have become a bit slower than you’d like at these times. You can often resolve this by upgrading your package with your provider. It’s sometimes possible to rate-limit the amount of data provided to each device, but not all routers support this and it requires a degree of technical expertise.


What broadband speed can I get?

This can usually be ascertained using our broadband postcode speed checker, which will give you results based on your postcode.

The speeds available to you are a guide and will depend on the infrastructure factors discussed above – the evolution of which will in turn depend on the roll-out schedule of the phone and cable providers.

If you’re unsatisfied with your available options you should check back regularly. Sometimes, contacting your provider or desired provider and ‘registering your interest’ will speed up provision of services in your area. If enough people do the same, then a given provider will be more likely to respond to the perceived demand – so if you go down this route, encourage local friends and family to do the same.


What broadband speed do I need?

This will be determined by the following factors:

1. How many people are there in your property?

More users = more bandwidth. Especially if you have teenagers in your home… trust us here!

2. What sort of activities do you/they indulge in online?

Depending on the sort of things you and others sharing your connection use your broadband for, you may find you can either get by with fairly average broadband or need the fastest cable or superfast fibre options.
If you mainly use the internet for browsing, e-mail and a bit of light social media activity then you will probably find that you’re perfectly happy with a basic connection such as ADSL 2+.

If you enjoy a bit of Netflix or Amazon Prime on top of the above and there are multiple users in your home – and don’t want to find yourself struggling with buffering and interruptions, then a basic fibre connection would probably suit you – especially if you opt for High Definition (HD) or Ultra High Definition (UHD) 4K content.

If there are people in your household who are heavier users; streaming a lot of HD or UHD video or high-quality audio, or who enjoy a lot of online gaming or download large files regularly for example, then you’re likely going to want to opt for one of the faster or even superfast fibre or ultrafast cable options.


Do I need fibre optic broadband?

Again, this is going to be determined largely by the way in which you and others sharing your connection make use of it. For smaller households with modest internet usage, fibre may not be necessary. However, with the cost of basic fibre packages being pretty similar to most top-end ADSL 2+ contracts, you may find that it makes sense to go for the faster option at a similar price point. If you’re in doubt, start small and speak to your provider about upgrading your connection when the need arises.


What broadband speed do I need for streaming?

This will depend on the quality and definition of the content that you’re streaming. Your needs will be lower if you’re only streaming to a tablet or smartphone than if you’re wanting to stream the latest 4K UHD content to a large flat screen TV. Netflix will automatically reduce the definition level of content being streamed if it detects that the connection is unsuitable for the desired level. This minimises buffering and ensures that you can receive the smoothest content delivery possible.

Netflix list their recommendations as follows:

Minimum required speed: 0.5 Mbps (512Kbps)
Recommended minimum: 1.5 Mbps
SD quality recommended minimum: 3.0 Mbps
HD quality recommended minimum: 5.0 Mbps
UHD quality recommended minimum: 25.0 Mbps

Amazon list similar basic requirements.

Spotify, being purely audio requires less bandwidth than video streaming, however choosing to stream music at the highest bitrate, or lossless audio will require more than standard 120-160 Kbps CD quality audio. Audiobooks require very little data to stream.


What broadband speed do I need for online gaming?

Gaming requirements are slightly unusual in that another factor comes into play that is less important in other applications – latency or ‘lag’. It’s also arguably more important than outright connection speed, because online gaming requires near real-time communication between players and the server – the amount of latency directly impacts on how smooth your gaming experience will be.

Latency is quantified using ‘ping times’. This is the amount of time in milliseconds that it takes a single packet of data to go from your computer to a specified server and back again. The higher the ping time, the less suitable your connection will be for online gaming. The term ‘jitter’ is often used in conjunction with latency and refers to the amount of variation in latency – this can be used as an indication of line quality and stability in general, as well as specifically for online gaming broadband needs.

You can test the ping time of your existing connection through most online speed testers. If you have some basic technical knowledge, you can also do this very easily from the Command Prompt of any Windows PC.
Speed does come into play when it comes to downloading games and game updates however – console games in particular can amount to several gigabytes of data. Downloading a 30 GB game over a comparatively slow connection is going to require a lengthy wait.

For their Xbox One console, Microsoft list the required broadband speed as a mere 3.0 Mbps, with Sony stating 5 Mbps for the PS4. Microsoft specify that ping times should be below 150ms, but in reality you’re going to want to achieve a ping far lower than that for a seamless experience.

Most UK providers will realistically be able to provide latency figures of below 40ms. One easy way to eliminate additional latency and reduce ping times is to ensure that you use a wired rather than wireless connection.


What broadband speed do I need for VoIP or video calling apps such as Skype?

Microsoft currently list the following requirements for varying definition levels of voice and video calling – please note that as this activity requires sending and receiving data, that the speeds quoted apply to BOTH the downstream AND upstream connection capabilities:

Voice calls:
30kbps minimum, 100kbps (0.1Mbps) recommended

Video calling / screen sharing:
128kbps minimum, 300kbps recommended

High quality video calling:
400kbps (0.4Mbps) minimum, 500kbps (0.5Mbps) recommended

HD video calling:
1.2Mbps minimum, 1.5Mbps recommended

3-way group video conferencing:
512kbps (0.5 Mbps) minimum, 2Mbps recommended

5-way group video conferencing:
2Mbps minimum, 4Mbps recommended

7 or more:
4 Mbps minimum, 8Mbps recommended


Can I speed up my connection without changing provider?

This will depend on your current package and what options your existing provider has in place as a potential upgrade path. If you’re on a legacy ADSL or first generation fibre package that you’ve had for some time then it’s highly likely that your provide will also offer a number of fibre packages.

Changing your broadband package will usually involve a new router, and these are invariably supplied by the provider. Speak to your provider to find out what they can offer you in terms of upgrading your broadband. If they are unable to provide you with anything better than your current option and you’re dissatisfied with that, come back here and use our postcode checker to find out if there are other ISPs that can offer you something more suitable.


Will I definitely get the broadband speed that I pay for?

In truth – possibly, but also very possibly not!

It is a longstanding source of dissatisfaction amongst UK broadband customers, with a significant percentage of users never receiving their quoted possible speeds.

You may have noticed that recently there has been a subtle but important shift in the way broadband is marketed; whereas previously companies would sell ‘20Mbps Broadband’, it’ll now be offered as ‘up to 20Mbps Broadband’ – Ofcom, the UK communications watchdog has insisted on this being made clear as a result of dissatisfaction from a large number of users who felt that they’d been promised unattainable speeds and were not getting what they paid for.