What Storage Size Do I Need on a Phone? 128GB vs 256GB vs 512GB Explained

How we put this guide together

To put this guide together, we reviewed the storage options and UK pricing on current flagship and mid-range phones in July 2026, checking capacities and tier pricing against Apple and Samsung's official UK specification pages. File size figures for photos, video and apps are based on manufacturer guidance and app store listings. Where relevant, we have drawn on our own experience of advising customers on handset choice in UK mobile retail.

How much storage do phones come with in 2026?

Most current flagship phones start at 256GB. Apple's entire iPhone 17 range, including the entry level iPhone 17e, starts at 256GB, with no 128GB option offered. The standard iPhone 17 comes in 256GB and 512GB, while the iPhone 17 Pro Max goes up to 2TB.

Samsung follows a similar pattern. The Galaxy S26 and S26+ come in 256GB and 512GB, and the Galaxy S26 Ultra adds a 1TB option. Many budget and mid-range Android phones still start at 128GB, which keeps their prices lower.

One important detail: the stated capacity is not all usable. The operating system and pre-installed apps typically take up 15 to 20GB, so a 256GB phone gives you roughly 220 to 240GB of space you can actually fill, depending on the device.

What actually uses your storage

Four things account for almost all storage use on a typical phone.

Photos and videos are the biggest factor for most people. A single photo from a modern phone camera is usually 2 to 5MB, which sounds small, but camera rolls run into the thousands of images over a phone's lifetime. Video is far heavier: one minute of 4K video at 60 frames per second takes roughly 400MB, and professional formats such as Apple's ProRes can use around 6GB per minute.

Games are the second biggest factor. Casual games are small, but major titles such as Genshin Impact or Call of Duty Mobile can take 30 to 50GB each once high resolution assets are downloaded. A handful of large games can fill half of a 256GB phone on their own.

Everyday apps are lighter individually, typically 100 to 500MB each, but their cached data grows over time. Messaging apps in particular accumulate gigabytes of received photos and videos.

Downloaded media rounds out the list. Offline playlists, downloaded films for flights, and podcast libraries all add up, though streaming instead of downloading keeps this close to zero. The trade off is that streaming uses mobile data when you are away from Wi-Fi, and our guide to what is a good data allowance covers how much that adds up to.

Is 128GB enough?

For a light user, yes. If you stream music and video rather than downloading, take a moderate number of photos, rarely record video, and do not play large games, 128GB will comfortably last a two year contract.

The risk with 128GB is the length of ownership. Phones are now kept for longer, and manufacturers support them for longer, with Samsung offering seven years of software updates on the Galaxy S26 series. Photo libraries and app sizes only grow, so a 128GB phone that feels roomy in year one can feel tight by year three or four. If you plan to keep your phone beyond a typical contract term, 128GB is the size most likely to become a problem.

Is 256GB enough for most people?

For the large majority of buyers, 256GB is the right answer, which is partly why manufacturers have made it the new standard starting size. It gives enough headroom for years of photos, a reasonable video library, several large games, and every everyday app, without paying for space that never gets used.

You should consider going bigger than 256GB only if one of the following applies: you record 4K video regularly, you keep more than four or five large games installed at once, or you are buying a phone you intend to keep for five years or more and would rather never think about storage.

When 512GB or more makes sense

The step up to 512GB typically costs £100 to £200 depending on the phone. That is worth paying for heavy video recording, serious mobile gaming, or professional use where large files need to live on the device. Filming in 4K for family events, holidays and social content is the most common reason UK buyers genuinely need it.

The 1TB and 2TB tiers on phones such as the Galaxy S26 Ultra and iPhone 17 Pro Max are aimed at people who shoot professional quality video on their phone. One minute of 8K footage can take over 600MB, so creators filming daily can fill 256GB within weeks. For everyone else, these tiers are more capacity than a phone will realistically use.

Does cloud storage change the calculation?

Partly. Cloud services let you keep full resolution photos and videos online while your phone holds smaller optimised versions, which significantly stretches a smaller storage size. Apple's iCloud+ starts at 50GB for around £0.99 per month in the UK, and Google's paid storage, now sold under its Google One and Google AI plans, starts at 100GB for around £1.99 per month. The free tiers are 5GB and 15GB respectively.

Cloud storage cannot replace local storage entirely. Apps, games, system files and anything you want available offline still need space on the device. It also adds a running cost: a 200GB plan at around £3 per month is over £70 across a two year contract, which narrows the saving from choosing a smaller phone. Cloud storage works best as a way to make 256GB last longer, not as a reason to buy less storage than you need.

Can you add storage later?

On most current phones, no. Flagship ranges from Apple, Samsung and Google have no microSD card slot, so the capacity you choose at purchase is fixed for the life of the phone. Some budget and mid-range Android phones still include expandable storage, and it is worth checking the specification if flexibility matters to you. You can browse mobile phones and compare storage options and prices side by side.

Because storage cannot be changed later, it is the one specification where erring on the side of more is a reasonable default if you are between two sizes.

How to check how much storage you actually use

The most reliable guide to what you need is what you currently use. On an iPhone, go to Settings, then General, then iPhone Storage. On Android, go to Settings, then Storage, or Settings, then Device care, then Storage on Samsung phones.

If your current phone is under half full after a year or more of use, the equivalent size will be fine on your next phone. If you are at 80 per cent or more, buy the next size up. Storage pressure also affects the total cost of a deal, since a bigger capacity raises the handset price and therefore the monthly cost on a contract. If you are weighing that up, you can compare pay monthly deals to see how each storage tier changes the monthly price.

Summary

Most buyers should choose 256GB, which is now the standard starting size on flagship phones and comfortably covers several years of photos, apps and games. Choose 128GB only if you are a light user who streams rather than downloads, and be aware it is the size most likely to feel tight if you keep your phone for many years. Choose 512GB or more if you record a lot of 4K video, keep many large games installed, or want a phone to last five years or more without storage management. Check your current usage in your phone settings before deciding, and remember that on almost all current flagships the size you pick cannot be changed later.