Does it feel like your phone is suddenly getting through far more mobile data than it used to? Maybe you've received a warning that you're close to your monthly allowance, or you've checked your account and wondered where all those gigabytes have gone.
You're certainly not alone. Modern phones can use a surprising amount of data, particularly as apps become more video-heavy and streaming quality improves.
The good news is that high data usage usually has an explanation. Better still, once you know where your data is going, it becomes much easier to work out how much mobile data you actually need.
Why Is My Phone Using So Much Mobile Data?
Mobile data is used whenever your phone accesses the internet through the mobile network rather than Wi-Fi.
Checking a few emails hardly uses anything compared with watching an hour of high-quality video. The problem is that many modern apps now contain videos, automatic downloads and background activity that can quietly increase your usage.
1. Video streaming
Video is one of the quickest ways to use a large amount of mobile data.
The amount used depends heavily on the streaming quality. Watching something at a lower resolution might use a few hundred megabytes an hour, while high-definition or 4K video can use several gigabytes in the same time.
A couple of films or several hours of video while you're away from Wi-Fi can therefore make a noticeable dent in even a fairly generous data allowance.
2. Social media is much more video-heavy now
Social media used to mean downloading relatively small images and bits of text. That's no longer the case.
Short videos, stories, reels and clips can automatically start playing as you scroll. Spend an hour watching a constant stream of video and your phone may use considerably more data than simple web browsing would.
Look inside your favourite social media apps for options such as Data Saver, Reduced Data Usage or lower video quality. The exact wording will vary between apps.
3. Apps are updating or downloading in the background
Your phone doesn't always wait for you to open an app before it starts using the internet.
Apps can refresh information, download new content, synchronise messages and perform other tasks in the background.
One small background refresh won't make much difference, but lots of apps doing it regularly can start to add up.
4. Photos and videos are being backed up
Modern smartphone photos can be several megabytes each, while high-resolution videos can be much larger.
If your phone is allowed to upload photos and videos to cloud storage using mobile data, recording a day full of photos and video could result in a significant amount of data being uploaded without you really noticing.
If you're trying to reduce your usage, check whether your photo backup service can be set to upload over Wi-Fi only.
5. Your phone has switched away from Wi-Fi
Sometimes you may think you're using Wi-Fi when your phone has actually started using mobile data instead.
This can happen if the Wi-Fi signal becomes weak, disconnects or your phone has a feature designed to use mobile data when the Wi-Fi connection isn't performing well.
It's worth checking the Wi-Fi icon before starting a large download or streaming something lengthy.
6. You're using your phone as a hotspot
Tethering a tablet or laptop to your phone can consume considerably more data than you might expect.
A connected laptop may download software updates, synchronise cloud storage, load full desktop websites or stream high-quality video.
Your phone is effectively becoming a broadband connection for another device, so everything that device downloads comes out of your mobile data allowance.
7. Apps and games are getting bigger
Downloading a large app or game over mobile data can quickly use several gigabytes.
The same applies to major software updates. Whenever possible, downloading large apps, games and phone updates over Wi-Fi can help keep your mobile usage under control.
Which Activities Use the Most Mobile Data?
There's no single exact figure because usage varies depending on the app, video quality, audio quality and device settings.
However, these rough estimates give you an idea of why some activities have a much bigger impact on your monthly allowance than others.
| Activity | Approximate data use | Impact |
|---|---|---|
| Web browsing and email | Around 50MB to 100MB per hour | Low |
| Music streaming | Around 40MB to 150MB per hour | Low to moderate |
| Social media | Around 100MB to 200MB+ per hour | Moderate |
| Short-form video feeds | Around 500MB to 1GB per hour | High |
| Video calls | Around 500MB to 1GB+ per hour | High |
| HD video streaming | Around 1.5GB to 3GB per hour | Very high |
| 4K video streaming | Around 5GB to 7GB+ per hour | Very high |
These are only planning estimates. Actual usage can vary considerably, particularly with video.
How Much Mobile Data Do I Actually Need?
This is the big question, and the answer depends much more on what you do away from Wi-Fi than how much you use your phone overall.
Someone could spend five hours a day on their phone but use very little mobile data if they're connected to home or work Wi-Fi most of the time.
Another person could spend less time on their phone but use far more mobile data because they're regularly streaming video while travelling.
According to Ofcom's latest pricing and consumer engagement research, SIM-only pay-monthly customers were consuming an average of around 13GB of mobile data per month by Q2 2025.
That doesn't mean 13GB is the right allowance for everyone, but it does show that you don't necessarily need 100GB or unlimited data simply because large allowances are widely available.
Worth considering if you're normally connected to Wi-Fi and mainly use messaging, maps, email and occasional browsing when you're out.
A sensible range for plenty of people who use social media, browse regularly, stream some music and occasionally watch video away from Wi-Fi.
Better suited to frequent social media use, regular video streaming, video calls and people who spend a lot of time away from Wi-Fi.
Useful if you regularly stream HD video, download large files or sometimes use your phone as a hotspot for other devices.
May make sense if mobile data is one of your main internet connections and you don't want to keep checking how much you've used.
📱 Not Sure How Much Data You Need?
Try our free Mobile Data Calculator. Tell it roughly how much video, social media, music, browsing, gaming and other mobile data you use and it will estimate a suitable monthly allowance.
Try the Mobile Data CalculatorCheck How Much Data You Already Use
Before changing your mobile plan, the best place to start is your actual usage.
Check your mobile phone operator's app, online account or recent bills to see how many gigabytes you've used over the last few months.
Don't just look at one month. Holidays, travelling, time away from work or a broken home broadband connection can all make one month unusually high.
Look at your normal monthly usage and give yourself a little breathing room. If you typically use around 12GB, for example, a 20GB allowance could make more sense than jumping straight to 100GB.
How Do I Find Out Which Apps Are Using My Data?
Your smartphone can normally show you which apps have used the most mobile data.
On an iPhone
Open Settings and look for Mobile Service or Mobile Data. Scroll down and you should see a list of apps along with their mobile data usage.
You can also stop individual apps from using mobile data if you'd rather they only connect when Wi-Fi is available.
On an Android phone
Look in Settings for options such as Network & Internet, Connections or Data Usage.
The exact menu names vary between phone manufacturers, but most Android phones provide a breakdown showing which apps are responsible for your mobile data usage.
How Can I Reduce My Mobile Data Usage?
If you're regularly getting close to your allowance, you might not need a bigger plan straight away.
A few small changes can make quite a difference.
- Connect to trusted Wi-Fi when it's available.
- Reduce video streaming quality when using mobile data.
- Turn on Data Saver options inside video and social media apps.
- Download music, podcasts and programmes over Wi-Fi before travelling.
- Set cloud photo and video backups to Wi-Fi only.
- Avoid downloading large apps and games over mobile data.
- Check which apps are allowed to use data in the background.
- Be careful when using your phone as a hotspot.
Does 5G Use More Data Than 4G?
Not automatically.
Downloading exactly the same file over 5G and 4G should use roughly the same amount of data.
What can change is your behaviour.
Faster mobile connections make it easier for apps to stream higher-quality video, load content more quickly and download larger files without you noticing the wait.
So 5G itself isn't necessarily eating your allowance. You may simply end up doing more with the faster connection.
Should I Just Get Unlimited Data?
Unlimited mobile data is convenient, but that doesn't automatically make it the best option.
If you regularly use less than 10GB or 20GB each month and spend most of your time connected to Wi-Fi, you could end up paying for an allowance you'll never come close to using.
On the other hand, unlimited data can be genuinely useful for people who stream lots of video, tether laptops or tablets, travel frequently or simply prefer not to worry about an allowance.
Check your recent usage with your current mobile phone operator. Your own usage history is usually a much better guide than choosing a plan based purely on the size of the allowance being advertised.
Is 20GB of Data Enough?
For many everyday smartphone users, 20GB can be a comfortable allowance, particularly if home and work Wi-Fi cover most of the day.
It gives you considerably more room than a very small plan while still avoiding the jump to huge allowances that you may never use.
Regular HD video streaming is where things change. At roughly 1.5GB to 3GB an hour, video can eat through 20GB relatively quickly.
What Happens If I Don't Use All My Data?
That depends on your mobile plan.
Some plans may allow unused data to roll over into another month, while others simply reset your allowance when the next billing period begins.
If you're consistently using only a small percentage of your allowance, it may be worth checking whether a smaller plan could save you money.
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If your phone suddenly seems to be using loads of data, start by checking which apps are responsible. Video streaming, social media videos, cloud backups, large downloads and hotspot use are usually much heavier than browsing or messaging.
You probably don't need the biggest data allowance available either. Check what you've actually used over the last few months, give yourself a little breathing room and choose your plan around that.
And if you still haven't got a clue whether you need 5GB, 20GB or 100GB, that's exactly why we built our free Mobile Data Calculator.
