A US Letter PDF exported at 200 DPI is 1,700 × 2,200 pixels. An A4 page at 200 DPI is 1,654 × 2,339 pixels. Multiply each page dimension in inches by the target DPI, then round to the nearest whole pixel.
Download the complete reference: CSV with all 64 page, orientation, and DPI rows · JSON with formulas, scope, and limitations. Both are licensed CC BY 4.0.
Calculate PNG dimensions
US Letter at 200 DPI exports to 1,700 by 2,200 pixels in portrait orientation.
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PDF to PNG pixel dimensions by DPI
| Page size | 72 DPI | 96 DPI | 150 DPI | 200 DPI | 300 DPI | 600 DPI |
|---|---|---|---|---|---|---|
| US Letter 8.5 × 11 in | 612 × 792 | 816 × 1,056 | 1,275 × 1,650 | 1,700 × 2,200 | 2,550 × 3,300 | 5,100 × 6,600 |
| A4 210 × 297 mm | 595 × 842 | 794 × 1,123 | 1,240 × 1,754 | 1,654 × 2,339 | 2,480 × 3,508 | 4,961 × 7,016 |
| US Legal 8.5 × 14 in | 612 × 1,008 | 816 × 1,344 | 1,275 × 2,100 | 1,700 × 2,800 | 2,550 × 4,200 | 5,100 × 8,400 |
| Tabloid 11 × 17 in | 792 × 1,224 | 1,056 × 1,632 | 1,650 × 2,550 | 2,200 × 3,400 | 3,300 × 5,100 | 6,600 × 10,200 |
The formula
Pixel width = page width in inches × DPI.
Pixel height = page height in inches × DPI.
PDF page geometry is normally expressed in points, where 72 points equal one inch. If you know the PDF width in points, the equivalent calculation is pixels = points × DPI ÷ 72. The calculator rounds the final result to the nearest whole pixel.
Which DPI should you use?
72–96 DPI
Small previews, thumbnails, chat attachments, and on-screen reference images. Fine print may soften.
150 DPI
Readable web documents and presentation slides when file size matters more than close zooming.
200 DPI
A practical balance for OCR, documentation, and readable page images. A Letter page becomes 1,700 × 2,200 pixels.
300 DPI
Printing, archival inspection, small typography, and stronger OCR input. Expect much larger images and memory use.
More DPI does not recover detail that is absent from the source. It only samples the PDF page at a larger raster size. Vector text and shapes scale cleanly; low-resolution embedded photos remain limited by their original pixels.
Why PNG file size cannot be predicted from DPI alone
The calculator reports uncompressed RGBA working memory, not the final PNG file size. PNG compression depends heavily on page content. A mostly white page with black text compresses well; a full-page photograph or noisy scan may be many times larger at the same dimensions.
Memory still matters because the browser must render the full pixel buffer before compressing it. A 600 DPI Letter page is 5,100 × 6,600 pixels and needs about 128.4 MB for one four-channel pixel buffer, before temporary copies and PNG encoding overhead.
Verified output example
In the 22-workflow browser PDF benchmark, pages 1 and 3 of a Letter PDF were exported at 200 DPI. Independent image inspection measured both PNGs at exactly 1,700 × 2,200 pixels with opaque white paper areas.
Going the other direction? The PNG DPI and PDF print-readiness checker reads a PNG’s real IHDR, pHYs, transparency, profile, metadata, and CRC evidence, then calculates its effective A4 or Letter placement PPI. To inspect source rasters already embedded in a document, use the PDF effective image PPI checker.