How to convert a PDF to A4 size without cutting anything off
By the PdfDady team · Updated · 6 min read
To convert a PDF to A4, you scale each page onto a new 210 × 297 mm page. Choose "fit" if nothing may be cut off, and accept thin blank strips at the top and bottom. Choose "fill" if you want the page covered edge to edge, and accept that a little is trimmed from the sides.
Our Change PDF Page Size tool does this in your browser: pick A4, pick fit or fill, and download. The rest of this guide explains which to choose, why the problem exists, and how to avoid a print shop handing you a page with the bottom line missing.
Why your PDF isn't A4 in the first place
A4 is part of the ISO 216 A series, used across most of the world, including India. Many PDFs, though, come from software set up for the United States, where the standard sheet is Letter. Templates from US websites, some online forms, documents made on a laptop with US regional settings and many e-books all default to it.
The two sizes look alike but are not the same shape:
| Size | Millimetres | Inches | Compared with A4 |
|---|---|---|---|
| A4 | 210 × 297 | 8.3 × 11.7 | |
| US Letter | 215.9 × 279.4 | 8.5 × 11 | 6 mm wider, 18 mm shorter |
| US Legal | 215.9 × 355.6 | 8.5 × 14 | 6 mm wider, 59 mm longer |
| A5 | 148 × 210 | 5.8 × 8.3 | Half of A4 |
Letter is slightly wider and noticeably shorter. So a Letter page printed on A4 at 100% loses a few millimetres at the sides and leaves a gap at the bottom. An A4 page printed on Letter can lose its last line or a footer with the page number.
Scanned documents and phone "scans" are another source of odd sizes. A page photographed at a slight angle and cropped by an app might be 205 × 290 mm, or an arbitrary size based on the photo's pixels. Converting to A4 makes every page uniform.
Convert it
- Open Change PDF Page Size and add your PDF (one file, up to 100 MB).
- Choose A4. Letter, Legal, A3, A5 and a custom size in millimetres are also available.
- Choose Fit or Fill (see below), and add a margin if you want white space around the content.
- Download
resized-pages.pdf.
Each page is scaled and centred on its new A4 page. Landscape pages can get a landscape A4 page, so a wide table isn't squeezed into portrait. Text is scaled, not turned into an image, so it stays sharp and selectable.
Fit or fill: which to pick
Fit keeps the whole page. The content is scaled until it touches the nearest edge, and the rest is left blank.
Fill covers the new page completely. The content is scaled until it reaches the farther edge, and whatever overflows is trimmed.
For the common case, Letter to A4, the numbers work out like this:
| Starting size | Fit to A4 | Fill A4 |
|---|---|---|
| US Letter | Scaled to about 97%, about 13 mm blank at top and bottom | Scaled to about 106%, about 10 mm trimmed from each side |
| US Legal | Scaled to about 84%, about 15 mm blank at each side | Scaled to about 97%, about 24 mm trimmed from top and bottom |
Use Fit for anything official: application forms, certificates, bank letters, anything where a missing line matters. The slight shrink is hard to notice. Use Fill only when the edges are just margin or background, such as a flyer with a coloured border you want to reach the paper edge.
Fill trims evenly, so a document with text close to the edge loses it. Look at the result before you print or upload it.
Page size is not file size
"Resize PDF" can mean two things. This tool changes the paper size of each page. It does not make the file smaller, and the result can be about the same size as the original.
If a portal says "maximum 1 MB" or "under 200 KB", it means the file size. For that, use Compress PDF, and see our guide on reducing a PDF's size for upload. If you need both, change the page size first and then compress.
Printing at a print shop or office printer
- Print at actual size. Once the file is A4, set scaling to 100% or Actual size on A4 paper. "Fit to page" on an already-A4 file adds a second, unnecessary shrink.
- Check the printer's paper setting. A printer set to Letter while loaded with A4 may complain about a paper mismatch, or shift everything. On Windows and most shop PCs, the paper size is in the print dialog under printer properties.
- If you only need it printed once, the print dialog's own "Fit to page" option on A4 paper gives a result similar to this tool's Fit. Converting the file is better when you send it to someone else, upload it, or want it to print the same way everywhere.
Problems and fixes
The form fields stopped working. The pages are redrawn on new A4 pages, so form fields, comments, links and bookmarks are not kept. Fill in the form first, run it through Flatten PDF so the answers become part of the page, then change the size. Or keep the original for filling in and use the A4 copy only for printing.
There's a wide white strip on some pages. That page had a very different shape, such as a long receipt or a landscape scan. Fit is doing its job. Try Fill if the edges are only blank margin, or crop the page first with Crop PDF so less white space is scaled.
Mixed portrait and landscape pages. Leave orientation matching on, so each page keeps its own direction on A4. When printed, landscape pages simply come out sideways on the sheet.
The text looks smaller than before. It is slightly smaller after a Fit from Letter or Legal. For Legal, the 84% shrink is noticeable on small print. If the small print matters, ask the recipient whether they can accept the original Legal size instead.
The file is password-protected. Remove the password first if you know it, using our guide on removing a PDF password, then convert.
Questions people ask
What is A4 size in cm and pixels?
A4 is 21 × 29.7 cm. In pixels it depends on the resolution: at 300 DPI it is about 2480 × 3508 pixels, and at 150 DPI about 1240 × 1754.
Can I convert just one page to A4?
The tool applies the size to every page. If only one page is a different size, the others are rescaled to A4 too, which does no harm if they were already A4.
Will converting to A4 change the quality?
No. The content is scaled as vector content, not re-rendered. Scanned pages were images to begin with and stay as they were, just scaled.
Is my PDF uploaded?
No. The conversion runs in your browser and the file stays on your device.