Storage Capacity Calculator — How Much Fits on a Drive?
A storage capacity calculator converts a drive's size into the number of real files it can hold — the question behind “is 256 GB enough?” and “how many photos fit on this card?”.
Quick answer: Divide the capacity by the average file size. A 128 GB card holds roughly 16,000 camera JPEGs at 8 MB each, 9,400 songs at 256 kbps, 11 hours of 4K30 video or about 42,600 phone photos at 1.8 MB (HEIC).
Enter the advertised size or the size your device reports
Use the average size from your own files for a sharper estimate
| Capacity | How many photos |
|---|---|
| 32 GB | 17,777 |
| 64 GB | 35,555 |
| 128 GB | 71,111 |
| 256 GB | 142,222 |
| 512 GB | 284,444 |
| 1 TB | 555,555 |
| 2 TB | 1,111,111 |
| 4 TB | 2,222,222 |
| 128 GB card | ≈ 16,000 × 24 MP JPEG · 9,400 songs · 11 h of 4K · 42,600 phone photos |
|---|---|
| 256 GB SSD | ≈ 32,000 JPEGs · 28 h of 4K · 6,400 RAW files at 40 MB |
| 1 TB drive | ≈ 125,000 JPEGs · 444 h of 1080p · 88 h of 4K at 25 Mbps |
| Reality discount | Subtract 5–15% for the file system, thumbnails and sidecar files |
Start from what you actually store
Capacity questions are always about a mix: phones fill with photos and videos, laptops with documents and caches, cameras with RAW files and 4K clips. Convert each category separately with the calculator's item types, then add the totals — mixing them into one “average file” hides the fact that 4K video is 3,000× larger than a document.
The file-system and metadata tax
Every drive loses a few percent to its own bookkeeping: NTFS and APFS reserve space for metadata and journals, cameras write sidecar files, and phones store thumbnails alongside originals. The conservative row in the calculator subtracts 7% up front so a planned 16,000-photo card does not become a surprise at photo 15,200.
Sizing for the next two years
Storage planning fails when it targets today's library instead of next year's. A simple rule: take the current total, add the growth you have seen over the past 12 months, then buy the next standard size up. Drives also degrade in performance past 85–90% full, so leave at least 10% headroom on SSDs — as important as raw capacity.
When to use this calculator
- Deciding between a 128 GB and 256 GB phone or tablet.
- Choosing an SD card size for a camera or drone before a trip.
- Checking whether an external drive can absorb a photo library.
- Planning cloud tiers against how much you actually upload.
- Working out how many hours of footage a shoot will need.