Scan DPI Selector
Stop guessing at scanner settings — work out the resolution a document or photo actually needs, so you don’t rescan it later at a higher setting.
Scan resolution
Or pick a document type
Why the right DPI matters
Scan too low and text comes out blurry or unreadable by OCR software; photos lose fine detail the moment you zoom in or print them larger. Scan far higher than you need and every file balloons in size, which slows down batch scanning, eats storage space, and makes documents slower to search and share.
The right setting depends on what you're scanning and what you plan to do with the digital copy — a quick reference scan of a receipt needs far less resolution than a family photo you might want to reprint at a larger size someday.
Frequently Asked Questions
How does the exact-DPI calculation work?
It divides your desired output width in pixels by the original's physical width in inches. If you want a scan of an 8.5-inch-wide letter page to come out 2,550 pixels wide, that's 2,550 ÷ 8.5 = 300 dots per inch — the DPI setting on your scanner that gets you exactly there.
Why does the result round up to a 'standard' setting?
Most scanners only offer a fixed menu of resolutions — commonly 75, 100, 150, 200, 300, 400, 600, 1200, and 2400 DPI — rather than an arbitrary number. Rounding your requirement up to the next available setting guarantees the output meets or exceeds what you asked for, instead of falling just short.
What DPI should I use if I don't know the target pixel size?
Pick a document type instead. A baseline of 300 DPI is a widely used minimum for scanning ordinary text so it stays sharp and OCR-readable, 400 DPI is often recommended for small or fine print, 600 DPI is common for photographs and prints, and film negatives or slides typically need much higher resolution — around 2400 DPI — because the original is so small.
Does a higher DPI always mean a better scan?
Not necessarily. Scanning far above what you'll ever need produces enormous files without a visible quality benefit, and it can dramatically slow down a scanning batch. Matching the DPI to your actual output size or document type keeps files a reasonable size while still looking sharp.
Educational guidance only. Archival and legal digitization standards vary by institution — check your organization's requirements for anything that must meet a specific record-keeping standard.