Why the number on the box is not the number you get
Phone storage is advertised in gigabytes, but not all of it is available to you. The operating system and preinstalled apps take a share before you add anything. The amount varies by phone and system version, but expect to lose a noticeable portion of the listed capacity. A phone sold with a given size will show a smaller free figure on first setup.
Also keep some headroom. A phone that is nearly full can slow down, fail to install updates, or refuse to take photos. Leaving some free space, often suggested as around a tenth or so of the total, is a sensible safety margin, though there is no exact rule.
The main space users
Most storage goes to a handful of things.
Photos and video. For most people this is the biggest item. Video takes far more space than photos, and higher resolutions and frame rates take more again. A short clip at a high quality setting can be larger than dozens of photos. Burst shots, live photos and duplicate edits add up.
Apps. Apps vary widely in size. Messaging and utility apps are modest, while games can take a large share, and some apps grow over time as they store cached data. Social media and streaming apps can collect large caches.
Offline media. Downloaded music, podcasts, videos for travel and offline maps all use space. A few downloaded movies can be larger than all your apps.
Messages and attachments. Chat apps save received photos, videos and voice notes. Over years this can be surprisingly large.
System data and updates. Updates need temporary room to install. Cached files and system data also use space, which the phone usually manages itself.
A simple way to estimate
You do not need exact numbers. Look at your current phone’s storage screen, which shows a breakdown by category. Then follow these steps.
- Note how much is used now and how long you have had the phone.
- Look at photos and video: does your library grow quickly? If you record a lot of video, add generous room.
- Add what you want available offline, such as music, movies or maps.
- Add room for the system, updates and growth over the years you plan to keep the phone.
For example, suppose a hypothetical user finds that photos and video take 40 GB, apps take 30 GB, and offline media takes 10 GB, for 80 GB in use. If the library is growing by about 15 GB a year and they plan to keep the phone for three years, that adds 45 GB, for 125 GB. Adding a margin of about one tenth of the total puts the target near 140 GB, so the next size up from that, rather than the smallest, is the sensible choice. This is only an illustration with made-up numbers; your own figures will differ.
General guidance by habit
- Light users who mostly message, browse and take occasional photos, and who store photos elsewhere, can often manage on a smaller capacity.
- Typical users who take plenty of photos, use many apps and keep some music or shows offline generally want a middle size.
- Heavy users who record video often, play large games or keep much media offline benefit from the largest sizes, or from a plan to move files off the phone regularly.
The cost of upgrading is a consideration. Storage cannot usually be added later, since many phones lack a memory card slot, so decide at purchase. If you keep phones for many years, buying a bit more can extend the useful life. If you replace your phone every year or two, paying extra may be wasteful.
Free up space without buying more
Several habits can reduce what you need.
- Move photos to the cloud or a computer. Using cloud storage lets you keep photos accessible while freeing space on the phone, though it may involve a monthly fee and depends on a connection. Our guide to photo backup explains how to organize and protect a library, and a plan for data backup keeps your files safe if the phone is lost.
- Offload unused apps. Both major systems can remove an app while keeping its data, so you can reinstall later.
- Clear caches and old downloads. Browsers and social apps keep temporary files that can be cleared.
- Delete large videos you no longer need, and review what chat apps have saved.
- Stream instead of download when you have a good connection. Our piece on streaming quality shows how connections affect this.
- Use a memory card if your phone supports one, or an external drive for transfers on some models.
Be careful when deleting: make sure photos are backed up before removing them from the phone, and that your sync really worked. Deleting a synced item on one device can sometimes remove it from the cloud as well, depending on settings.
Other points to weigh
Faster, larger storage costs more, and phones with more storage often cost noticeably more than the base model. Compare that price with the cost of a cloud storage subscription over the life of the phone. If you prefer to keep everything on the device and avoid subscriptions, buying more storage may make sense. If you are comfortable with online services, a smaller phone plus cloud storage may be cheaper.
If you plan to resell, larger capacities can be more attractive to buyers. Before passing a phone on, follow the steps in our guide to wiping old devices.
Overall, base the choice on your own library and habits, add a margin, and remember that backups and clean-up habits can stretch any size further.