What DPI Should You Scan Old Photos At? A Practical Guide

"What DPI should I use?" is the first question almost everyone asks before scanning a box of photos. The honest answer is: it depends on what you want to do with the files later. The good news is that the decision is simpler than scanner menus make it look.

What DPI actually means

DPI (dots per inch — scanners really mean pixels per inch) tells the scanner how many pixels to capture for every inch of the original. A 6×4-inch print scanned at 300 DPI becomes an image of 1800×1200 pixels. At 600 DPI the same print becomes 3600×2400 pixels.

Two consequences follow:

• Print size. At 300 pixels per inch you can reprint the photo at its original size with full quality. At 600 DPI you can print it at roughly twice the size.
• File size. Doubling the DPI quadruples the number of pixels — and roughly quadruples the file size.

The short answer

For most family prints, 600 DPI is the sweet spot: enough detail to enlarge or crop, without the huge files of 1200 DPI.

Why not always scan at the maximum?

Prints only hold so much detail. A typical drugstore print from the 1980s or 1990s doesn't contain much information beyond what 600 DPI captures; going higher mainly records paper texture and grain, while files get four times bigger and scans take much longer. For a few hundred photos, that difference is hours of scanner time and many gigabytes of storage.

Small prints are the exception. A wallet-size photo scanned at 300 DPI is barely 750 pixels wide — too small to print any larger. Scan small originals at 600–1200 DPI so the digital file has room to grow.

Multi-photo scans: one more reason to choose 600 DPI

When you scan several prints at once and split them afterwards, every photo's resolution comes from that single scan. Splitting doesn't add pixels; it just cuts the scan into pieces. If you scan a page of four prints at 300 DPI, each exported photo is a 300 DPI photo.

With AI Auto Cropper the crops are taken from your original scan, not from the smaller preview used for detection, so you keep whatever resolution you scanned at. That makes it worth choosing the resolution with the final individual photos in mind — usually 600 DPI.

File format

• JPG at high quality (90%+) is fine for everyday archives and sharing. It keeps files small.
• PNG or TIFF keeps every pixel exactly, at the cost of much larger files. Use them for a master archive if storage isn't a concern.

A common compromise is to keep a lossless master of especially important photos and high-quality JPGs for everything else.

Color depth and settings

Scan in 24-bit color, even for black-and-white prints, to capture their original tone. Leave automatic "restoration" features off for your master scans; you can always edit a copy later, but you can't undo what the scanner software discarded.

A simple decision rule

• Mostly screens and sharing? 300 DPI.
• Want options later, or scanning several prints at once? 600 DPI.
• Tiny originals? 1200 DPI.

Then scan, split, and get the photos into the hands of the people who'll enjoy them. If you're starting now, try the scan cropper on your first sheet.