Quick answer
Most small businesses without heavy video/photo work need 500GB-2TB — start smaller and expand later, since adding storage is cheaper than paying for capacity you never use.
It’s easy to overestimate what you need “just in case” — but storage costs money, and you can always add more later.
What actually eats up space
Documents (Word, Excel, PDF) are tiny — thousands of files fit in a few GB. What actually eats up space is photos, video, and high-resolution drawings.
A practical guide
If your work is mostly documents/accounting, 500GB comfortably covers years. If you work professionally with photography/video, start at 2TB and up.
- Documents/accounting: 500GB usually lasts for years
- Photos/drawings: 1-2TB
- Professional video: 2TB+ and expandable