What Resolution Do You Need to Scan Old Photos?
For most family prints, 300 DPI is enough. Go to 600 DPI for small prints, like wallet-size and old square snapshots, or for any photo you might enlarge or restore. Going higher rarely helps, because a print doesn’t hold much more detail than that.
What the archivists say
The Library of Congress suggests 300 DPI for 4×6, 5×7 and 8×10 prints. Its experts note that scanning prints much higher mostly magnifies dust and grain (Library of Congress, The Signal). Their practical advice: pick one sensible setting for the whole collection, and rescan the few special photos at a higher setting.
When to go higher than 300
- Small originals. A 2½×3½ wallet print at 300 DPI is only about 750×1,050 pixels, which looks soft on a modern screen.
- Enlargements. Printed below about 100 pixels per inch, a scan starts to look pixelated (Unique Photo Q&A). So if you might print a 4×6 at 12×18, scan it at 600 DPI or more.
- Restoration. Fixing scratches and tears is easier when you have more pixels to work with.
- Negatives and slides are a different case. They’re tiny and hold far more detail, so 1,000–2,000 DPI or more is normal.
What that means in pixels
| Print size | At 300 DPI | At 600 DPI |
|---|---|---|
| Wallet (2.5×3.5 in) | 750×1,050 (0.8 MP) | 1,500×2,100 (3.2 MP) |
| 4×6 in | 1,200×1,800 (2.2 MP) | 2,400×3,600 (8.6 MP) |
| 5×7 in | 1,500×2,100 (3.2 MP) | 3,000×4,200 (12.6 MP) |
| 8×10 in | 2,400×3,000 (7.2 MP) | 4,800×6,000 (28.8 MP) |
Is an iPhone camera good enough?
For most prints, yes. A 12-megapixel iPhone photo is 4,032 pixels on its long side. If a 4×6 print fills about 90% of the frame, that works out to roughly 600 pixels per inch. That’s a nominal figure: lens softness and compression mean the real detail is lower, but it comfortably beats 300 DPI. Phones with a 48 MP mode give you about twice the linear resolution.
The weak spots are large prints and photos you plan to enlarge a lot. For those, a flatbed scanner still wins.
The rule of thumb
- Everyday 4×6 and 5×7 prints: 300 DPI (a phone is fine)
- Wallet prints and small square snapshots: 600 DPI (a phone held close is fine)
- Photos to enlarge or restore: 600+ DPI (flatbed recommended)
- Negatives and slides: 1,000–2,000+ DPI (film scanner)