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

Here's a scenario I've run into more times than I can count: you create a PDF on your laptop, everything looks perfect on screen, you send it to someone to print, and then they come back complaining that half the content is cut off. Or the margins are all wrong. Or it printed on paper that's way too small.

The problem? Page size. Your PDF was created with one page size (maybe something weird like 13x19 inches because that's what your design software defaulted to), but the person printing it expected standard Letter or A4. This is super common, and it's exactly what resizing your PDF pages fixes.

Let me walk you through how to resize PDF pages — quick, free, and without losing your mind.

Common Page Sizes You'll Encounter

Before we get into the how-to, here's a quick reference for the most common page sizes:

• Letter (US): 8.5 x 11 inches — the standard US paper size
• A4 (International): 8.27 x 11.69 inches — the standard in most of the world
• Legal: 8.5 x 14 inches — longer than Letter
• Tabloid: 11 x 17 inches — twice Letter size
• A3: 11.69 x 16.54 inches — twice A4

Most printers default to Letter or A4. If your PDF is a different size, it won't print correctly without adjustment.

Method 1: PeacefulPDF (Browser-Based, Free)

PeacefulPDF's resize tool is probably the easiest way to do this. You upload your PDF, choose your target page size, and it handles the rest.

What I really like about this tool is that it shows you the original page size and lets you resize to standard sizes (Letter, A4, Legal, etc.) or set custom dimensions. You can also choose what happens to content that doesn't fit — does it get scaled down, or do you just change the page dimensions and keep the content as-is?

Here's my typical workflow:

1. Go to PeacefulPDF's resize tool
2. Upload your PDF
3. Select your target size (Letter, A4, whatever you need)
4. Choose whether to scale content to fit
5. Download the resized PDF

Takes maybe 15-20 seconds for a typical document. I've used this to resize PDFs that were created in Europe (A4) for printing in the US (Letter), and vice versa. Super handy.

Method 2: Adobe Acrobat

If you have Adobe Acrobat Pro, resizing pages is straightforward. Go to Tools > Organize Pages > More > Crop Pages. From there, you can set the exact page dimensions you want.

Acrobat gives you a lot of control — you can set specific margins, change the page box (media box, crop box, trim box, etc.), and even resize only certain pages rather than the whole document.

The downside? It's $20/month. For a task this simple, that's overkill. But if you already have it, it's there and it works well.

Method 3: Preview on Mac

Mac users have a built-in option that's completely free. Preview can resize PDF pages, though it's a bit hidden.

1. Open your PDF in Preview
2. Go to Tools > Adjust Size
3. You can enter new dimensions in inches or pixels
4. Make sure "Scale proportionally" is checked if you want to maintain aspect ratio
5. Click OK and save

One thing to note — Preview's "Adjust Size" is designed for images, so it works okay for PDFs but isn't optimized for them. You might find that it doesn't give you the precise control you need for professional documents. But for quick adjustments, it's fine.

Method 4: Print to PDF (The Simple Trick)

Here's a method that doesn't require any special tools: just print to a new PDF with the page size you want.

Most operating systems let you "print" to a PDF file rather than physical paper. During this process, you can specify the page size. The resulting PDF will be in the size you chose.

On Windows:

1. Open your PDF in Edge or Chrome
2. Press Ctrl+P
3. Choose "Microsoft Print to PDF" as your printer
4. Click "Preferences" or "Properties" and look for page size settings
5. Set your desired size (Letter, A4, etc.)
6. Print

On Mac:

1. Open your PDF in Preview
2. Go to File > Print
3. In the print dialog, look for "Paper Size" and select your desired size
4. Choose "Save as PDF" as the destination
5. Save

This method is nice because it uses built-in functionality — no extra tools needed. The downside is that it re-renders the PDF, which can sometimes cause minor quality changes or font issues. For most documents, though, it's perfectly fine.

What Happens to Your Content?

This is the important question. When you resize a PDF page, what happens to the stuff already on the page?

There are two main approaches:

• Keep content as-is, change page dimensions: The page gets bigger or smaller, but the content stays exactly where it was. If you make the page smaller, content might get cut off. If you make it bigger, you might have extra white space.
• Scale content to fit: Everything on the page gets proportionally resized to fit the new page dimensions. This is usually what you want — it ensures all your content stays visible and fills the page appropriately.

Most tools give you the choice. I'd recommend starting with "scale to fit" — it tends to give the most predictable results. If the scaling looks wrong (maybe text looks too small, or images got distorted), then try the other option.

Fixing Margins vs. Changing Page Size

Sometimes the issue isn't the page size itself — it's the margins. A PDF might be the right size (Letter, for example) but have such huge margins that your content looks tiny when printed.

This is different from resizing. To fix margins, you need a tool that lets you adjust the "page box" — essentially telling the printer to use a smaller printable area within the page.

Tools like Adobe Acrobat have this (Crop Pages function), and some online PDF editors do too. It's a more advanced feature, but it can save a document that looks wrong due to margin issues.

When Page Size Goes Wrong

Let me tell you about the worst page size disaster I encountered. A colleague sent me a PDF that was clearly made in some desktop publishing software — the page size was set to 11.7 x 16.5 inches (close to A3 but not quite). They wanted me to print it on standard Letter paper.

When I printed it without adjusting, everything was massively scaled down and looked ridiculous. I had to resize it to Letter, scale the content to fit, and it came out okay — but this is exactly the kind of situation where knowing how to resize saves the day.

Another common issue: PDFs from web-based tools. Some of these create PDFs that are sized for screen viewing (like 800x600 pixels or some weird dimension) rather than print. When you try to print them, it's a mess. Resizing to Letter or A4 fixes this.

Batch Resizing Multiple PDFs

Need to resize a dozen PDFs to the same page size? Most tools handle one PDF at a time, which is tedious for batch work.

If you're comfortable with command-line tools, there's a tool called pdftk that can do this. But honestly, for most people, the easiest approach is:

1. Resize each PDF individually using PeacefulPDF or your preferred tool
2. Or use a PDF merge tool to combine them all first, then resize the combined file once

That second approach is surprisingly effective. Combine 20 small PDFs into one file, resize once, done.

PDF Page Size and Digital Viewing

One thing worth mentioning: page size matters less for digital viewing than for printing. If someone's reading a PDF on an iPad or laptop screen, the PDF viewer will typically scale the content to fit regardless of the actual page dimensions.

But if you're printing — and especially if you're printing professionally (at a print shop, for a brochure, etc.) — the page size absolutely matters. Always check the requirements before sending files to a professional printer. They usually need specific sizes, and wrong sizes mean reprints or additional fees.

Quick Summary

• Easiest method: Use PeacefulPDF's resize tool — browser-based, free, handles scaling
• Built-in Mac: Preview's Tools > Adjust Size
• Built-in Windows: Print to PDF and select your desired page size
• Adobe Acrobat: Tools > Organize Pages > Crop Pages (paid)
• Choose "scale to fit" unless you have a specific reason not to

Resizing PDF pages is one of those tasks that seems complicated until you do it once. After that, it's dead simple. The tools have gotten really good, and for most cases, you can knock it out in under a minute.