When choosing a new mobile phone price plan, you’ll need to decide how much data you want. Find out how long each gigabyte (GB) of data will last you.

Nowadays, the key difference between mobile phone price plans is how many gigabytes of data it comes with. On some entry-level plans, this can be as little as 500MB (half a gigabyte), increasing up to 100GB on some of the most expensive plans. Some mobile phone price plans even include unlimited data so you won’t even need to worry about how much data you’re using.

In this article, we’ll explain mobile download allowances and we’ll help you to decide how many gigabytes of data you need. We’ll look at the different apps and activities you might use on your smartphone, and consider how long a gigabyte of data lasts on each one. Finally, we’ll discuss how you can find out your current data consumption and how you can reduce your mobile data usage.

Download Limits In The UK

Gone are the days when you could choose a mobile phone price plan simply based on the number of inclusive minutes and texts. Nowadays, the most important difference between mobile phone price plans is the amount of data it comes with (the number of inclusive gigabytes or GB of data).

On entry-level tariffs, you’ll normally get around 500MB (half a gigabyte) of data. As you pay more, the amount of data quickly increases, up to around 100GB on the most expensive plans. Some mobile networks even go one step further in offering an unlimited data plan meaning there’s no need to worry about how much data you’re using. Zero-rated data plans are also becoming more popular, giving you unlimited data for use on a selected range of applications.

The following table shows the range of data allowances currently available on UK mobile networks:

Mobile Network Pay Monthly Data Allowance Pay As You Go Data Allowance
ASDA Mobile 250MB to 15GB
BT Mobile 500MB to 50GB
EE 1GB to 100GB 50MB to 16GB
giffgaff 500MB to Always-On*
iD Mobile 500MB to 40GB 100MB to 4GB
O2 1GB to 100GB 2GB to 20GB
Plusnet Mobile 500MB to 12GB
SMARTY 1GB to Unlimited
Sky Mobile 2GB to 25GB
Tesco Mobile 1GB to 50GB 250MB to 8GB
Three 500MB to Unlimited 2GB to Unlimited
Virgin Mobile 1GB to Unlimited 2GB to 10GB
Vodafone 500MB to 100GB 100MB to 20GB
VOXI 6GB to 45GB

* giffgaff’s Always-On data gives you unlimited downloads, but only the first 80GB per month are at full 4G speeds. After the first 80GB per month, download speeds are capped at 384kbps between 8am and midnight.

On most mobile networks, you’ll be given a monthly data allowance that will expire if the data isn’t used during a given month. However, some mobile networks now offer a data rollover feature meaning your unused data can sometimes be carried over into a following month. SMARTY offers an unused data discount so you can get money back for any unused data.

The following table shows how monthly prices compare for plans with different amounts of data:

Amount of DataPay MonthlyPay As You Go
250MB Data--
500MB Data--
1GB Data£2.90£5.00
2GB Data£6.00£6.00
3GB Data£5.00£5.00
4GB Data£4.95£7.50
5GB Data£4.50£5.00
6GB Data£5.95£9.90
8GB Data£7.00£10.00
10GB Data£5.90£8.00
12GB Data£9.00£10.00
20GB Data£7.90£10.00
30GB Data£8.00£12.00
40GB Data£10.00£15.00
50GB Data£7.95£15.00
100GB Data£12.00£19.88
Unlimited Data£16.00£20.00

How Much Data Do I Need?

As of 2019, the average UK consumer uses around 3GB of mobile data per month. However, when choosing a mobile data plan for your own usage, it’s important to figure out how much data you personally need. This will differ based on your own individual usage patterns and requirements – there isn’t a one size fits all that will work for everyone.

Choosing a price plan with too little data could result in you getting cut off in the middle of the month. Alternatively, you might be charged expensive out-of-allowance rates for continuing to access the internet after your allowance runs out.

On the other hand, choosing a price plan with too much data could mean you’re overpaying for lots of data that you don’t actually use. Often, there will be promotions encouraging you to choose a price plan with much more data than you need (e.g. 100GB of data for £20/month). However, this is sometimes a false economy if you don’t actually need all of that data (it will cost you a lot more than a regular data plan with just the right amount of data for your usage).

How Long Will A Gigabyte Of Data Last For?

The following table gives an approximate guide to what you can do with a gigabyte of data. You can use it as an indication of how long each gigabyte of data is expected to last for:

Activity 1GB data is equal to…
Accessing web pages 600 web pages (approx. 12 hours browsing)
Basic e-mail/instant message 350,000 messages
Rich e-mail/IM (with attachments) 2,000 messages
Downloading or streaming music 200 songs
Downloading or streaming video (SD) 2 hours
Downloading or streaming video (HD) 30 minutes
Skype voice call 30 hours
Skype video call 4 hours
Listening to online radio 16 hours
Downloading or updating apps 25 apps

We’ve made a number of assumptions in coming to these numbers. You can read about these in more detail here.

For a 500MB data allowance, you should half all of the figures above (as a 500MB allowance is equal to 0.5GB). For a data allowance that’s larger than 1GB, simply multiply up the figures as appropriate (e.g. multiply by 4 if you have a 4GB download allowance).

In a given month, you’ll use multiple apps and activities on your smartphone. You should add up the data usage from each activity in finding out how much data you need in total.

Data Usage Calculator

If you’re unsure how much data you might need each month, several UK mobile networks provide an online data usage calculator:

This can be a good place to start to get an estimate of your mobile data usage. However, you should also read on and find out your actual data usage figures at the moment.

Average Data Consumption

As of 2019, the average UK consumer uses around 3GB of mobile data per month. This average data consumption has grown hugely over the past few years. For instance, according to Ofcom statistics, average data consumption was just 200MB (0.2GB) in 2012. This increased more than eight-fold to 1.9GB by 2017. Further increases are expected over the next few years with the launch of 5G and new applications.

Despite what is often said about average data usage, we think it’s important to choose the right data plan based on your own usage. For instance, some people will use a lot more data than average whereas others will use a lot less. For this reason, it’s important to look at your own individual usage, and to choose a data plan based on those requirements.

Saying that, if you’re looking to sign up for a fairly lengthy contract (e.g. for 24 months), it can be worthwhile choosing a slightly larger data plan than for your current usage. As data consumption is expected to grow over the next few years, you’ll want to future-proofing your plan for any increases in your own individual usage.

Data Usage: By App & Activity Type

Almost all apps and activities on your smartphone will consume some of your data allowance unless you’re connected to wi-fi. The following table gives you a rough guide on how much data is used by different apps and activities:

Mobile Data - Messaging Basic E-mail or Instant Message (e.g. Gmail, WhatsApp)
0.003MB per message (3KB, no attachments)
Mobile Data - Rich Email Rich E-mail or Instant Message (with attachment)
0.5MB per message (500KB)
Mobile Data - Browsing Web Browsing (e.g. Facebook, BBC, Daily Mail)
  1.7MB per web page, approximately 90MB per hour of web surfing
Mobile Data - Music Downloading or Streaming Music (e.g. MP3 files, Spotify)
  5MB per song
Mobile Data - Skype Voice Skype Voice Call
  35MB per hour
Mobile Data - Apps Downloading or Updating Apps
  40MB per app
Mobile Data - Online Radio Listening to Online Radio
  60MB per hour
Mobile Data - Skype Video Skype Video Call
240MB per hour
Mobile Data - Online Video Downloading or Streaming Online Video (e.g. YouTube, iPlayer)
500MB per hour (SD quality), 2GB per hour (HD quality)

Please note that the figures given above are only an approximation. Things like web pages and applications vary hugely in size, depending on things on like how rich in multimedia they are. Similarly, online video streaming can vary hugely in data usage depending on the service you use and the quality of your stream.

Our assumptions:

  1. Web Browsing: As of April 2019, the median web page size is 1.7MB when accessed from a mobile device.
  2. Music: Assuming an average bitrate of 160kbps, one minute of music will be approximately 1.2MB. Therefore, a four minute song will be approximately 5MB in size.
  3. Skype Calls: Our testing found a Skype voice call to consume 0.55MB/minute (70kbps). A Skype video call was found to consume 4MB/minute (500kbps).
  4. Online Video: Data consumption varies hugely depending on what you’re watching and the quality of the video stream. For instance, BBC iPlayer uses 225MB of data per hour in standard definition. Meanwhile, YouTube uses 600MB (standard definition), rising to 2GB (high definition). Netflix uses 1GB of data per hour (standard definition), increasing to 3GB per hour (high definition). We’ve used an average of 500MB per hour for standard-definition video and 2GB per hour for high-definition video.

How To Find Out Your Current Data Usage

Smartphone Data Usage Monitor

The best way to find out your current data usage is to check through your smartphone’s built-in data usage monitor.

  • iPhone: On your iPhone, go to Settings > Mobile Data.
  • Android: On Android, go to Settings > Wireless & Networks > Data Usage.

The information on this screen can be used to understand how much data you currently use. You’ll be able to see a breakdown of how and when that data was used. You can also set up automatic alerts for when your data usage exceeds a certain amount each month.

The information displayed on this screen is a good indicator of how much data you’re currently using. You can use it as a rough guide when deciding how much data you’ll need on a new mobile phone plan.

Mobile Network Apps

You can also check how much data you’ve used through your mobile network’s official application.

Compared to your smartphone’s built-in data usage monitor, this will sometimes give you a different figure. It’ll be the authoritative number that is used for billing purposes but is generally slightly less useful as a data point when choosing a new price plan (for instance, your mobile network’s numbers will exclude zero-rated data use and will not give you a full app-by-app breakdown).

You should use one of the following applications, as relevant for the mobile network you’re on:

Reducing Your Data Consumption

If you’d like to reduce your mobile data consumption, here are some of our top tips:

  • Use Wi-Fi whenever it’s available (e.g. at home, at work or outside). Any data that’s transferred over a wi-fi connection will not count towards the download limit on your mobile phone plan. For this reason, it’s a good idea to connect to wi-fi whenever you’re within range of an available network (e.g. at home, in the office or when you’re out at a supermarket or coffee shop). As this reduces your mobile data usage, you can save it for when you actually need it (e.g. when you’re outside with no access to wi-fi).
  • Download things like TV shows, podcasts, music playlists and maps before you leave home. Sometimes, you might be able to download content in advance whilst you’re still at home and connected to wi-fi. For instance, this feature is available on BBC iPlayer, on Netflix, on Spotify, on Google Maps and more. It requires a bit of planning in advance and some extra storage space on your smartphone but it will save you from needing to stream the content over a mobile data connection. This should normally give you smoother playback as well as reduced mobile data consumption.
  • Disable automatically playing videos on Facebook, Instagram and more. On social networking websites like Facebook and Instagram, videos located in your feed will often play automatically as soon as you scroll past. This consumes a lot of data as the videos are downloaded to your phone, even if you don’t actually want to watch them. See the step-by-step instructions on how to disable automatically playing videos on iPhone and Android devices.
  • Check your automatic software update settings and your photo & cloud storage backup settings. Normally, you’ll want to make sure automatic software updates only take place whilst you’re connected to a wi-fi network. On the iPhone, go to Settings > iTunes & App Store and make sure the “Use Mobile Data” setting is switched off. Meanwhile, on Android, go to the Google Play store and tap on Menu > Settings > Auto-update apps. You’ll want to make sure this is set to “Auto-update apps over Wi-Fi only”. If you use any photo or cloud storage backup apps (e.g. Apple iCloud or Google Photos), check to make sure this only backs up whilst you’re connected to wi-fi.
  • Use a web browser that compresses your data. For instance, Google Chrome can be used in Lite mode on Android. Alternatively, the Opera Mini browser is available for both iPhone and Android devices. These web browsers compress data before transferring it to you over the internet, hence reducing the amount of data required to load a web page. Please note that there may be some privacy implications in deciding to use one of these services. This is because they proxy all of your web traffic through another server.
  • Uninstall apps that use a lot of data, or restrict background data usage. Your smartphone’s data usage monitor should tell you how much data individual apps are consuming on your phone. You can uninstall data-hungry apps if you no longer want to use them. Alternatively, switch off “background app refresh” or “background data usage”. This will stop the application from being able to access the internet when aren’t inside and actively using the app (however, it can prevent things like notifications from working correctly). On the iPhone, go to Settings > General > Background App Refresh. Meanwhile, on Android, go to Settings > Wireless & Network > Data Usage > Data Saver.


KB, MB, GB and TB (Kilobytes, Megabytes, Gigabytes and Terabytes)

There are 1,000 kilobytes in a megabyte (1000KB = 1MB) and 1,000 megabytes in a gigabyte (1000MB = 1GB). Occasionally, the concept of a terabyte has started creeping into usage: there are 1,000 gigabytes in a terabyte (1000GB = 1TB).

You can use the following table to convert between the four different measurements:

Measurement In Terabytes In Gigabytes In Megabytes In Kilobytes
Terabyte 1TB = 0.001 GB 1TB = 0.000 001 MB 1TB = 0.000 000 001 KB
Gigabyte 1GB = 0.001 TB 1GB = 1,000 MB 1GB = 1,000,000 KB
Megabyte 1MB = 0.000 001 TB 1MB = 0.001 GB 1MB = 1,000 KB
Kilobyte 1KB = 0.000 000 001 TB 1KB = 0.000 001 GB 1KB = 0.001 MB

For more information, see the full explanation from Wikipedia.

In general, most mobile data allowances are measured in terms of gigabytes (GB). However, on some lower-cost tariffs, the data allowance could be measured in megabytes (MB). For instance, some tariffs come with 500MB of data, which is equivalent to 0.5GB.

Unlimited Data

Some price plans come with unlimited data, meaning there’s no need to worry about how much data you’re using.

It’s important to read the terms and conditions when choosing an unlimited data plan. For instance, giffgaff offers Always-On data (this gives you unlimited downloads but only the first 80GB per month are at full 4G speeds). Alternatively, Three and SMARTY offer unlimited data with a fair usage policy of 1,000GB (1TB) per month.

For more information, see our full guide to unlimited data plans.

Zero-Rated Data

Some price plans come with zero-rated data (unlimited data for use on a range of services). On a zero-rated plan, data usage within certain apps and services will not be counted towards your normal monthly download limit.

To give an example, VOXI offers endless social media on plans from £10/month and endless video on plans from £15/month. You therefore shouldn’t count the usage of these inclusive applications when deciding how much data you need on your plan.

Download Speeds (Mbit/s)

Download speeds (the speed of your mobile internet connection) are sometimes compared to your monthly download allowance. However, it’s important to remember that download speeds are measured in megabits per second, as opposed to megabytes per second.

For instance, a 5 megabyte (5MB) music file actually consists of 40 megabits (as there are 8 bits in 1 byte). On a data connection that is 4Mbit/s, it would take you 10 seconds to download this 5MB file (5 * 8 / 4 = 10 seconds).

More Information

For more information, please refer to your mobile network’s website for information about the data plans they offer. You may also find it of interest to read our guide on recommended SIM cards and our in-depth article on mobile network download speeds.

Your Comments 449 so far

We'd love to hear your thoughts and any questions you may have. So far, we've received 449 comments from readers. You can add your own comment here.

  • I enjoy the no worry of unlimited. I can easily read articles like this and get lost following all the branch off topics and then have no time left.
    I would really be in a pinch if I used up all my data without concern, reading about duck wing feather mites in birds of the pine forested area of Kanuckistan or somewhere, and have no time left to read a bus schedule the next day.
    The extra cost is worth it to me. Hell, I used 2gb just trying to read the comparison chart for 2gb.

  • I just bought Pay As You Go card (it said £15 25GB on it, but I paid £1 for the card).

    I then bought £10 top-up for it and put it on…… I was lazy and couldn’t be bothered to go downstairs to see what the internet code was and so went on to mobile data.

    17 minutes later my £10 was used up.

    This was my first experience with my new Smart Phone. I will be going back to my Samsung Flip phone which DOES only cost me £10 per month for unlimited calls and texts. I do NOT need internet and photos and all this malarkey – I was getting on just fine (Amazon is useful but if I remember to check when they will arrive I do not really need them).

    This is daylight robbery by 3 (and no doubt other companies are similar). I am utterly shocked!

    I don’t know what I did wrong, but I expect other people will have as well – what if I had been lost in a forest – 17 mins for £10 wouldn’t have been very long to get unlost and I may have been eaten by a wolf…….

    Back to my happy-clappy phone!


    • Another point from me – Angela – I only went on to Google and TESCO website to see if I could log on to the internet – don’t recall anything else, and I updated some settings on my new phone….. I didn’t upload or download anything or add any Word or Excel docs; I looked up the word ‘squirrel’ and I don’t think much else….

      I am off to the 3G phone shop tomorrow, but for me – this was a bit like a horror movie!!

      I am off to use my laptop now – modern technology I understand!

      Angela (again). 🙂

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