How to Resize PDF Pages (Change Page Size to A4, Letter, or Custom)

I spent an embarrassing amount of time last year trying to figure out why my document kept printing with the edges cut off. The content looked fine on screen. The margins were reasonable. But every time I hit Print, the right side got chopped.

The problem? The PDF was created on a computer set to A4 paper (210 × 297 mm — the standard everywhere outside North America), but I was printing on US Letter paper (8.5 × 11 inches, which is slightly wider but shorter). The page content didn't fit properly, and my printer was silently cropping instead of scaling.

This is a more common problem than you'd think. Page size mismatches cause printing issues, submission rejections, and formatting headaches. And the fix is usually simple: resize the PDF pages.

A4 vs. Letter: The Eternal Conflict

Before we get into how to resize, let's talk about why this problem exists in the first place. There are two main paper standards in the world:

• A4: 210 × 297 mm (8.27 × 11.69 inches). Used in Europe, Asia, Australia, South America, Africa — basically everywhere except the US and Canada.
• US Letter: 8.5 × 11 inches (215.9 × 279.4 mm). Used in the United States and Canada.

They're close in size but not the same. A4 is narrower and taller. Letter is wider and shorter. When you create a document on one size and try to print it on the other, things get weird.

If you work with people internationally — and in 2026, who doesn't? — you've probably run into this. Your colleague in London sends you a PDF. You print it in New York. The bottom half-inch of every page is missing. Annoying? Yes. Fixable? Absolutely.

When You Need to Resize PDF Pages

Beyond the A4/Letter thing, there are other reasons you might need to resize:

• Submission requirements. Many organizations specify an exact page size. Grant applications, legal filings, academic journals — they want what they want, and a wrong page size can mean rejection.
• Merging documents with different page sizes. You merged several PDFs and now some pages are A4, some are Letter, and one random page is A3 for some reason. You want them all the same size for a consistent look.
• Preparing for print. Print shops often need specific dimensions. If you're printing a booklet, poster, or custom-sized document, the PDF page size needs to match exactly.
• Scaling for readability. Maybe you received a PDF designed for a large format (like a poster) and you want to scale it down to something more manageable on screen.
• Fixing scanned documents. Scanners sometimes produce PDFs with slightly off dimensions. The scan says it's 8.51 × 11.02 inches instead of exactly 8.5 × 11. Some printers and software get confused by this.

Method 1: PeacefulPDF Resize Tool

PeacefulPDF's resize tool handles the most common case: converting between standard page sizes. Open it, upload your PDF, pick your target size (A4, Letter, Legal, etc.), and download. Everything happens in your browser.

The tool scales the content to fit the new page size while maintaining proportions. So your text and images won't get stretched or squished — they'll be slightly smaller or larger, depending on whether you're going to a bigger or smaller page.

1. Open the Resize tool
2. Upload your PDF
3. Select the target page size
4. Download the resized PDF

For the A4-to-Letter conversion I mentioned earlier, this is the fastest solution. The whole process takes under 30 seconds.

Method 2: Print to PDF With Custom Settings

The print-to-PDF trick works here too, and it gives you some control over scaling:

1. Open the PDF in any viewer (Chrome, Preview, Acrobat Reader)
2. Press Ctrl/Cmd + P to print
3. Set the printer to "Save as PDF" or "Microsoft Print to PDF"
4. Change the paper size to your desired dimensions
5. Under scaling, choose "Fit to page" or set a custom scale percentage
6. Save

This method is built into every operating system and costs nothing. The "Fit to page" option does a decent job of scaling content to match the new page size. But it's not perfect — margins might change, and the scale factor might not be exactly what you want.

The bigger issue is that print-to-PDF can subtly alter the document. It re-renders everything through the print pipeline, which means embedded fonts might change, interactive elements (forms, links) might break, and image quality might shift. For a simple text document, no problem. For a complex document with forms and embedded media, proceed with caution.

Method 3: Adobe Acrobat Pro

Acrobat has a dedicated page resizing feature under Print Production → Preflight, or you can use the "Set Page Boxes" tool. It's powerful but the interface is... not intuitive. I've been using Acrobat for over a decade and I still have to Google how to resize pages every time I need to.

The simpler approach in Acrobat: use Print → Page Setup to change the paper size, enable "Fit" scaling, and print to PDF. Same as the generic method above, but Acrobat's print engine tends to preserve document structure better than Chrome's.

Acrobat also lets you set exact crop boxes, trim boxes, and bleed boxes — which matters for professional printing but is overkill for most people. If those terms mean nothing to you, you don't need this level of control.

Method 4: Ghostscript (Command Line)

For batch processing or exact control, Ghostscript is the gold standard:

gs -sDEVICE=pdfwrite -dPDFSETTINGS=/default -dFIXEDMEDIA -dDEVICEWIDTHPOINTS=612 -dDEVICEHEIGHTPOINTS=792 -o output.pdf input.pdf

Those numbers (612 × 792) are US Letter size in points (72 points per inch). For A4, you'd use 595 × 842. Ghostscript can scale, crop, or pad the content to fit the new dimensions.

It's free, it's powerful, and it handles batch operations beautifully. The learning curve is steep, but once you have the right command, you can resize thousands of PDFs in minutes.

Scaling vs. Cropping vs. Padding

When you resize a PDF page, there are three things that can happen to the content:

Scaling makes the content proportionally larger or smaller to fit the new page. This is what most tools do by default and what most people want. The content looks the same, just slightly bigger or smaller.

Cropping cuts off content that extends beyond the new page boundaries. If you're going from a larger page to a smaller one without scaling, content near the edges gets chopped. Bad for most use cases, but sometimes intentional (like removing unwanted borders).

Padding adds white space around the content when going from a smaller page to a larger one. The content stays the same size, but you get extra margins. This can look strange — your A4 content floating in the middle of a tabloid-sized page — but it's sometimes exactly what you want for printing purposes.

Make sure you know which one your tool is doing. Most free tools default to scaling, which is usually correct.

Mixed Page Sizes in One Document

This one trips people up. You have a PDF where most pages are Letter-sized but three pages are A3 (like spreadsheets or diagrams that needed more space). You want everything to be Letter.

Most resize tools apply the same transformation to all pages, which means those A3 pages will be scaled down significantly. The text and details on those pages might become tiny and hard to read.

My suggestion for this scenario: split the PDF into groups by page size, resize each group separately (maybe the A3 pages need a different scaling strategy), then merge them back together. It's more work, but the result is better.

Alternatively, consider whether those large pages should stay large. Maybe the spreadsheet needs to be printed on larger paper anyway. In that case, resize only the pages that need it.

Quick Fixes for Common Printing Issues

Before you go through the effort of actually resizing your PDF, try these printer-side fixes:

• "Fit to page" in print settings. Most printers and PDF viewers have this option. It scales the content at print time without modifying the PDF. This is often all you need.
• Change the paper tray. If your printer has multiple trays (one loaded with A4, one with Letter), make sure you're printing from the right tray.
• "Actual size" vs. "Shrink to fit". Some print dialogs default to "Actual size," which doesn't scale at all and just clips whatever doesn't fit. Switch to "Shrink to fit" or "Fit to printable area."

If the printer fix works, you might not need to resize the PDF at all. But if you're distributing the PDF to others (who might not know to adjust their print settings), it's better to fix the PDF itself.

The Bottom Line

Resizing PDF pages is one of those tasks that seems niche until you need it, and then it's suddenly urgent. The good news is that for the most common case — converting between A4 and Letter — any of the methods above work fine.

My personal go-to: browser-based tool for quick one-off conversions, Ghostscript for batch processing, and the print-to-PDF trick when I'm in a hurry and don't want to open another tool.

Whatever method you choose, always open the resized PDF and check that everything looks right before sending it out or printing it. Content scaling can occasionally produce unexpected results — a graph that was readable at A4 size might be too small at Letter size, or margins might need adjustment. A 30-second visual check saves you from embarrassment and reprints.

Now go fix those page size issues. Your printer will thank you.