How much data do I need? What 5GB, 10GB and 20GB get you

Key takeaways

• A sensible starting point is about 5GB a month if you're mostly on WiFi. Try 10GB to 30GB if you stream or scroll video away from WiFi, and 30GB or more (or unlimited) if your phone is your main way online.
• One hour of Netflix on a phone uses up to 0.7GB at medium quality and up to 3GB in HD. Video is usually the biggest part of a monthly total, while music, maps and messaging use very little.
• The surest way to choose a data allowance is to check your last three months of actual usage, then pick a size a little above your busiest month.

 

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You're comparing plans. 5GB, 20GB, 100GB, unlimited. Somewhere between "never runs out" and "why am I paying for this" sits the right number, and nobody tells you which one it is.

The good news is that it's easier to work out than the plan names suggest. This guide covers what light, medium and heavy users usually need, what eats your data, and how to check your own usage. Then you can pick a size and get on with your day.

How much data do I need each month?

How many GB you need depends on how much you do away from WiFi. Anything you do on home or work WiFi doesn't count toward your allowance. Use this table as a starting point.

Type of user	Monthly data	What it usually looks like
Light user	Up to about 5GB	Mostly on WiFi, with messaging, email, maps and some music on the go.
Medium user	About 10GB to 30GB	Regular video, social media or music away from WiFi, plus the odd video call.
Heavy user	30GB or more, or unlimited	Lots of video on the move, sharing data with a laptop (a hotspot), or no WiFi at home.

What actually uses your data?

Video, mostly. Almost everything else uses much less data.

Activity	Rough data use
Watching Netflix at low quality	Up to 0.3GB an hour
Watching Netflix at medium quality	Up to 0.7GB an hour
Watching Netflix in HD	Up to 3GB an hour
Watching Netflix in 4K Ultra HD	Up to 7GB an hour
Scrolling short-video apps like TikTok and Instagram Reels	Roughly 600MB to 850MB an hour
Streaming music	Roughly 40MB to 150MB an hour, depending on sound quality
Using maps for navigation	Typically a few MB an hour
Messaging and email	Very little, until photos, videos and big attachments get involved

Is 5GB, 10GB or 20GB a lot of data?

It depends on where you use your phone. 10GB is plenty if you're mostly on WiFi, but it goes quickly if you watch a lot of video on the move. This table shows how long each size would last if you used every bit for video, based on Netflix's maximum figures.

Monthly allowance	Video at medium quality (0.7GB an hour)	Video in HD (3GB an hour)
5GB	About 7 hours	About 1 hour 40 minutes
10GB	About 14 hours	About 3 hours 20 minutes
20GB	About 28 hours	About 6 hours 40 minutes
50GB	About 71 hours	About 16 hours 40 minutes

How do I work out my own number?

Your actual usage beats any general estimate. Here's the quick version:

1. Look at your last three months of usage. Your network's app or online account is the best place to start, as it shows the figure your plan counts.
2. Pick your busiest month, not the average. Plans are about avoiding the bad month.
3. Add a little extra data, say about a quarter more.
4. Check what happens if you go over. Some plans charge extra, some slow you down, and some let you buy more data.

If you'd rather check on the phone itself, menu names vary a little by model and software version, but it usually looks like this.

How to check how much data you have left on an iPhone

Open Settings, then Mobile Service, and scroll to the usage figures under Current Period. The counter doesn't reset each billing month, so note the date you last reset it before trusting the total.

How to check how much data you have left on an Android phone

Open Settings, then Network & internet (or Connections on Samsung phones), then Data usage. Most Android phones let you set the start date of your billing month, so the figure matches your plan.

Easy ways to use less data

If you're close to your limit, these three changes help the most:

• Download shows and playlists on WiFi before you head out.
• Turn off auto-play in social apps.
• Lower the streaming quality in video apps, as HD uses several times more data than medium quality.

What if I pick the wrong size?

That's the worry with most data plans. Pay for too much and the gigabytes go to waste. Pick too little and you run out of data in week three.

With SMARTY, plans run month to month with no lengthy contract, so a wrong guess doesn't last long. You can switch to a different size from your account at your next renewal, or add extra data if you run short before then. Our all plans page shows every size from 5GB up to unlimited. If you'd rather skip the maths, there's an unlimited plan. Keen to start straight away? An eSIM means no waiting for a SIM in the post.

FAQs

How much data do I need per month?

A light user needs up to about 5GB a month, a medium user needs about 10GB to 30GB, and a heavy user needs 30GB or more. The biggest factor is how much video you streamed away from WiFi.

Is 10GB of data enough for a month?

10GB is enough for a month of messaging, maps, music and browsing, and for about 14 hours of medium-quality video. Regular HD streaming on mobile data will use up 10GB much more quickly.

How do I check how much data I have left?

Check your network's app or online account for the figure that counts against your plan. Or open Settings and look under Mobile Service on an iPhone or under Data usage on an Android phone. Subtract that total from your monthly allowance to see what remains.