Storage Capacity Calculator
Work out how many photos, videos or files fit on a drive or phone, after system space and what is already used.
Your inputs
Results
Items that still fit
47,600
- Free usable space
- 190.4 GB
- Items that would fit on the empty drive
- 57,600
≈Estimate based on the stated model and assumptions
What this calculator does
Plan storage purchases or clean-ups by estimating how many items fit.
Formula and method
Free = capacity × usable share − used; Items = free ÷ item size
Worked example
Calculated by this tool with its default inputs:
Inputs
- Advertised storage capacity: 256 GB
- Usable share (after system files and formatting): 90 %
- Average item size: 4 MB
- Already used: 40 GB
Results
- Items that still fit: 47,600
- Free usable space: 190.4 GB
- Items that would fit on the empty drive: 57,600
How to read the results
Item sizes vary — use an average from your own files.
Assumptions and limitations
- Uses decimal GB and MB, as drive manufacturers do.
Questions
Why is usable space below the advertised size?
File systems, the operating system and reserved space take some of it.
Methodology and verification
- Result type
- Estimate based on the stated model and assumptions
- Formula version
- 1.0
- Automated verification
- 2 reference and validation test cases, checked against independently computed values. The site cannot be built if any of them fail.
- Editorial review
- Awaiting human editorial review. The explanation was drafted with AI assistance; the formula and examples are verified by the automated tests above.
Privacy
Everything you enter is calculated in this browser and is not sent to Numerith or anyone else. Inputs are added to a share link only if you choose to include them. Privacy policy