A scan’s physical size and resolution determine its nominal pixel rectangle. An 8.5 × 11-inch original at 300 dpi gives 2,550 × 3,300 pixels. At 24 output bits per pixel that is 25,245,000 tightly packed raw bytes: 25.245 decimal MB or about 24.076 MiB. A saved PDF or JPEG can be a different size.
Scan DPI, pixels and raw raster size
Calculate scan dimensions and an uncompressed raster. Target width and height are optional together; keep their axes aligned to the scan.
Worked example: 8.5 × 11 inches at 300 dpi produces 2,550 × 3,300 pixels under this rounding convention.
Enter the worksheet inputs.
Numbers stay in this page. No account, upload or automatic saving. Download or print to keep your result.
Read the result
The worksheet converts millimeters to inches using 25.4 mm per inch, multiplies each axis by dpi and rounds each pixel dimension upward. For 1-bit output it rounds each row up to a whole byte. File headers, format-specific row alignment, compression, metadata and additional pages are outside the estimate.
Enter both target pixel dimensions to calculate the smallest whole-number dpi meeting both axes without rotating the target. Doubling both pixel dimensions requires twice the dpi and produces four times the pixels. The calculator does not create detail beyond a scanner’s optical capability or assess legibility, OCR or photo quality.
Choose the real scan setting
Epson’s scan-setting instructions explain increasing resolution when enlarging the output. The correct setting still depends on your original and intended use. Check optical resolution and exported bit depth in the exact device documentation; internal sensor bits are not necessarily exported file bits. Epson’s published scanning specifications explicitly distinguish input and output data.
Use the document-scanner shortlist for equipment and ADF vs duplex scanning to define which sides must be captured. Before printing a scanned rectangle, use the paper-scaling worksheet .
Method and limits
This original calculator implements unit conversion and raster arithmetic, with numerical and browser checks. We did not scan originals or measure compressed file sizes. Sources checked October 15, 2026. Each starting value is an editable mathematical example; no scan is uploaded.
See Also
If you want to move from general advice into actual product choices, start with Paper Print Scaling Calculator: A4, Letter and Margins, Printer and Scanner Energy Cost by Operating Mode, and How to Clean a Standing Desk Top without Damage.
For a wider picture after the basics, Best Office Chair for Big and Tall People Under $500 and Best Ergonomic Office Chairs of 2026 are the next places to read.