Phones, apps & storage
Phone Storage Calculator
A 128 GB phone does not have 128 GB. Between the decimal-versus-binary gap and the system partition, you start about 20 GB down. This works out what is really left and what it holds — and tells you which capacity to buy for how you actually use a phone.
The 128 GB phone with 109 GB in it
Two things eat the difference before you install anything.
Decimal against binary. Manufacturers count a gigabyte as 1,000,000,000 bytes. The phone counts it as 1,073,741,824. That gap is 7.4% and it grows with capacity: a "128 GB" phone has 119 GiB as the operating system measures it, and a 1 TB phone loses 90 GiB to the same arithmetic.
The system partition. Android with a manufacturer skin typically occupies 10 to 20 GB, iOS around 10. Add the update staging area a phone needs and 128 GB becomes roughly 100 GB of usable space in practice.
What things actually take up
| Item | Size | Notes |
|---|---|---|
| Photo, 12 MP HEIC | 2–3 MB | JPEG of the same shot is roughly double |
| Photo, 48 MP ProRAW | 25–75 MB | A hundred of these is a gigabyte |
| Video, 1080p 30fps | ~90 MB/min | 5.4 GB per hour |
| Video, 4K 30fps | ~350 MB/min | 21 GB per hour |
| Video, 4K 60fps | ~440 MB/min | 26 GB per hour |
| Song, offline | 3–10 MB | Depends on the service's quality tier |
| Ordinary app | 50–200 MB | Grows over time with cached data |
| Large mobile game | 2–8 GB | Frequently doubles after the first update |
Why running near full is a problem
Flash storage needs free blocks to write into. A phone above roughly 90% full spends increasing effort shuffling data to find space, and the symptoms are the ones people blame on the phone being old: slow photo saving, apps reloading, updates that refuse to install. Keeping 10% free is not tidiness, it is how the hardware is designed to work.
Which capacity to buy
- 128 GB — fine if you shoot 1080p, keep photos in the cloud and do not install large games. Tight for anyone else.
- 256 GB — the sensible default for someone who records 4K occasionally and keeps a few years of photos on the device.
- 512 GB and up — for regular 4K video, large game libraries, or offline media on the road. Twenty minutes of 4K 60fps a week fills 128 GB in under a year.
Questions people ask about this
Why does my 128GB phone only show 107GB?
Two reasons stack. Manufacturers count a gigabyte as 1,000,000,000 bytes while the phone counts 1,073,741,824, which removes 7.4% before anything is installed — 128 GB becomes 119 GiB. Then the operating system and its update staging area take 10 to 20 GB. What is left is about 100 to 107 GB, and that is normal rather than a fault.
How many photos fit in 128GB?
Around 35,000 to 50,000 HEIC photos at 2–3 MB each, if the phone held nothing else — which it never does. With a typical app load, an operating system and some video, roughly 25,000 photos is a realistic figure. ProRAW or 48 MP shots at 25–75 MB each cut that to about 1,500.
How much storage does an hour of 4K video use?
About 21 GB an hour at 4K 30fps and 26 GB at 4K 60fps, so roughly 350 to 440 MB per minute. Two hours of 4K footage fills half a 128 GB phone. 1080p 30fps is around 5.4 GB an hour — a quarter of the space for footage most people cannot distinguish on a phone screen.
Is 128GB enough in 2026?
For light use with cloud photo backup, yes. For anyone who records 4K video, installs large games, or keeps years of photos on the device, no — those three habits each consume tens of gigabytes a year. 256 GB is the capacity most people stop thinking about storage at.
Where these numbers come from
Rates on this page were last checked against the published price lists on . Grading companies change fees and pause tiers without notice — confirm the total on the submission form before you pay.
- Media sizes measured from typical device output — per-item averages, adjustable in the calculator