Storage
Capacity by SD card, SSD or phone
It rarely makes sense to choose the same capacity for every device. This guide summarizes what matters most when you buy for a phone, an SD card or an SSD.
Phone
On a phone, capacity is usually shaped by photos, videos, apps and enough margin for several years.
SD card
For an SD card, camera type, resolution, bitrate and how often you empty it matter much more.
SSD or external drive
For SSDs, it helps to think not only about capacity, but also growth, organization and backup copies.
Phone
On a phone, capacity often runs short when you mix photos, video, apps, caches and documents without cleaning frequently. If you shoot a lot of video or want to keep several years of content locally, 256 GB is usually much more comfortable than 128 GB.
SD card
With SD cards, the usage pattern matters a lot. An action camera, a mirrorless camera and a casual compact camera do not generate the same weight per minute or per session. It helps to think in recording days, not only in the total number printed on the card.
SSD or external drive
For SSDs and external drives, the typical mistake is buying only for current space. If the disk will hold backups, projects or media libraries, it is better to account for growth, organization and at least a reasonable margin.
How to use this criterion
This guide is not trying to give one universal number. It helps you decide which variable matters most for each purchase: years of local storage on a phone, recording days on an SD card, or growth and organization for SSDs and external drives.
Key assumptions
- Real file weight depends on format, resolution, bitrate, compression and cleaning habits.
- The same capacity behaves very differently for casual photos, 4K video, ProRes or RAW.
- Long-lived libraries and backups need margin, not only a minimum fit.
Limits of this guide
- It does not replace measuring your current library if you already know the real file size.
- It does not evaluate performance, durability or write speed of the device.
- It uses practical editorial references to guide the choice, not a universal exact capacity.
Official sources
The format and compatibility references that matter most for this decision are grounded in official documentation from Apple, Microsoft and Adobe.
- Apple Support: using HEIF and HEVC
- Microsoft Learn: HEIF format overview
- Adobe Help: RAW compatibility and workflow
If you want to ground a specific purchase, combine this guide with the storage calculator and the backup growth calculator.