iCloud Backup Size Calculator

What actually goes into an iCloud backup

Apple's definition is narrow and worth reading twice: your backup includes the information and settings stored on your device that do not already sync to iCloud. Everything in that sentence is doing work. In practice the backup carries app data for the apps you downloaded, your device settings, your Home Screen layout and app organisation, purchased ringtones, your Visual Voicemail password, and your Apple Watch backup, which rides along inside the iPhone's.

Photos and Messages are the conditional part. Photos and videos are in the backup only when iCloud Photos is off. Messages are in the backup only when Messages in iCloud is off. Turn either sync on and that content leaves the backup, because it is already in iCloud on its own.

The big exclusion is apps themselves. App binaries are never backed up. Apple re-downloads purchased apps from the App Store when you restore, so only their data travels. A 256 GB iPhone can back up in 10 or 15 GB because the backup is a picture of what your phone knows that iCloud does not, rather than a copy of the phone. If you want the other half of that question, what actually fills the device, the iPhone Storage Size Calculator sizes it.

The iCloud Photos trap: why the backup shrinks but the bill does not

Same phone, twice, using this calculator's own constants. Take 12,000 HEIC photos (30.0 GB) and three hours of 1080p30 video (10.8 GB), so 40.8 GB of camera roll, alongside 60 apps of typical weight (3.6 GB), three years of messages (1.2 GB) and 0.8 GB of settings and system.

Identical account usage, identical bill, two wildly different numbers on screen. The backup fell by 40.8 GB and not one byte left the account. So the popular advice, turn on iCloud Photos to make the backup fit, does not work. It makes the backup fit while leaving your storage exactly as full as it was, and Apple will still stop backing up, stop syncing and ask you to upgrade.

That is why the calculator above reports two numbers and judges your plan against the larger one. The only thing that moves a total is deleting bytes.

Working out whether your backup fits, and what to do when it does not

Apple bills iCloud+ monthly, and only monthly, so the yearly figure is simply twelve times the monthly price. Current US pricing:

Be honest about the trade at each step. Free to 50 GB is under twelve dollars a year, which is often the sane answer rather than a weekend of deleting. The gap between 200 GB and 2 TB is $84 a year, every year, which buys a lot of motivation to stay under 200 GB. If you are wrestling with the free tier specifically, the iCloud Free 5GB Storage Calculator totals everything else competing for those five gigabytes, and the iCloud Storage Cost Calculator prices every tier if you would rather compare than delete.

When you decide to shrink instead, work in this order:

1. Old device backups. A phone you no longer own can be holding several gigabytes. Settings, your name, iCloud, iCloud Backup lets you switch it off and delete it. Apple keeps disabled backups for 180 days.
2. Heavy apps. The same screen lists apps by size. Switch off the ones you would not miss. Some are always backed up and cannot be turned off.
3. Message attachments. Years of photos and videos people sent you, sitting in a thread nobody rereads. The iMessage Storage Calculator works out how much yours is worth.
4. The camera roll. Usually the biggest number on the list, and the one everyone puts off.

Shrinking the camera roll, which is usually the real problem

Duplicates, burst runs, screenshots you dealt with months ago and videos you have never rewatched are the bulk of most libraries. They are also the part nobody enjoys triaging, which is why the camera roll survives every other cleanup attempt intact. The Camera Roll Cleanup Estimator breaks the saving down by category if you want a finer figure than this page's single slider.

Swipe44 is built for the doing rather than the estimating. You go through photos one swipe at a time, right to keep and left to mark, working from Recents, Random or a single month so a 12,000-photo library becomes a series of ten-minute sessions instead of one impossible afternoon. Duplicates are grouped by perceptual hashing that runs on your phone. Everything you marked collects in a pending pile and clears in one batch behind a single system confirmation, and the app reports how much space came back, which is the number this calculator just asked you to hit. It is all on-device: no account, nothing uploaded, and iCloud-offloaded originals are never downloaded while it works, which matters if your library lives in iCloud.

One last thing, and it catches everybody: deleted photos sit in Recently Deleted for 30 days and keep counting against your storage the whole time. Empty that album or the gigabytes you just cleared will not show up in either number for a month.