Resize PDF to Custom Dimensions — Inches, Points, and Millimeters
- Enter any width and height in points (72pt = 1 inch = 25.4mm)
- Covers book trim sizes, postcards, posters, ID cards, and more
- Common custom sizes: 6x9, 5.5x8.5, 4x6, 11x17, 8x10
- Free browser tool — no upload, no watermark
Table of Contents
A4, Letter, and Legal cover most needs. But if you are formatting a book for Amazon KDP, creating postcards, preparing a poster, or matching any non-standard page size, you need custom dimensions. The free resize tool accepts any width and height from 1 inch (72pt) to 50 inches (3600pt) — enough to cover everything from business cards to architectural drawings.
How to Enter Custom Dimensions
Open the PDF Resizer, drop your file, and click "Custom" from the size grid. Two input fields appear for Width and Height in points.
Quick conversion reference:
- 1 inch = 72 points
- 1 mm = 2.835 points
- 1 cm = 28.35 points
To convert from inches to points: multiply by 72. For 6 x 9 inches, enter 432 (width) and 648 (height). For 5.5 x 8.5 inches, enter 396 and 612.
To convert from millimeters: multiply by 2.835. For 148 x 210 mm (A5), enter 420 and 595.
The tool accepts any value from 72 to 3600 on each axis. That range covers pages from 1 x 1 inch up to 50 x 50 inches.
Common Custom Sizes and Their Point Values
| Format | Inches | Points (enter these) | Use Case |
|---|---|---|---|
| Book (Trade) | 6 x 9 | 432 x 648 | Amazon KDP, standard paperback |
| Digest | 5.5 x 8.5 | 396 x 612 | Journals, half-letter booklets |
| Postcard | 4 x 6 | 288 x 432 | Mailer postcards, handouts |
| Photo Print | 8 x 10 | 576 x 720 | Photo prints, certificates |
| Tabloid | 11 x 17 | 792 x 1224 | Large posters, newspapers |
| ID Card | 3.375 x 2.125 | 243 x 153 | Badge-sized documents |
| Square | 8 x 8 | 576 x 576 | Art books, portfolios |
| A5 | 5.83 x 8.27 | 420 x 595 | Small booklets, planners |
| A3 | 11.69 x 16.54 | 842 x 1191 | Architectural, diagrams |
| B5 (JIS) | 7.17 x 10.12 | 516 x 729 | Japanese standard, manga |
Bookmark this table for quick reference. These are the dimensions most people search for when they need something beyond A4/Letter/Legal.
Sell Custom Apparel — We Handle Printing & Free ShippingBook and Publishing Formats
Self-publishers are the biggest users of custom PDF dimensions. Amazon KDP, IngramSpark, Lulu, and other POD platforms each have specific trim size requirements. If your manuscript PDF does not match the expected dimensions, the platform either rejects it or auto-scales it — which throws off margin alignment.
Amazon KDP popular trim sizes:
- 5 x 8 in (360 x 576 pt) — compact paperback
- 5.25 x 8 in (378 x 576 pt) — slightly wider
- 5.5 x 8.5 in (396 x 612 pt) — digest, very popular
- 6 x 9 in (432 x 648 pt) — trade paperback, most common
- 7 x 10 in (504 x 720 pt) — textbook format
- 8.5 x 11 in (612 x 792 pt) — full-page workbooks
If you formatted your book at one trim size and your publisher requires a different one, resizing the PDF is faster than reformatting the entire manuscript in your typesetting software. Content scales proportionally — just double-check margins and gutter width after resizing.
Landscape, Square, and Special Orientations
For landscape documents, simply swap width and height. A landscape 6 x 9 becomes 648 (width) x 432 (height). The tool does not have a separate landscape/portrait toggle — the dimensions you enter define the orientation.
Square formats (like art portfolios or Instagram-style printouts) use equal width and height: 576 x 576 pt for 8 x 8 inches, 720 x 720 pt for 10 x 10 inches.
Panoramic and banner formats are also possible. The tool supports up to 3600 points on each axis, so a 4-inch tall by 36-inch wide banner (288 x 2592 pt) is within range.
One limitation: the tool resizes all pages to the same custom dimensions. If your document has mixed page sizes (some portrait, some landscape), split it into groups, resize each group to different custom dimensions, then merge them back.
Points, Inches, and Millimeters: The Full Conversion Guide
PDF dimensions are natively measured in points — a unit from traditional typography where 72 points equals 1 inch. This can be confusing if you think in inches or millimeters.
From inches to points: multiply by 72. Example: 8.5 inches = 612 points.
From millimeters to points: multiply by 2.835. Example: 210 mm = 595 points (A4 width).
From centimeters to points: multiply by 28.35. Example: 21 cm = 595 points.
From points to inches: divide by 72. Example: 648 points = 9 inches.
If your custom size requirements are in pixels (like "resize PDF to 1920 x 1080"), you need to know the target DPI. At 72 DPI: pixels = points. At 150 DPI: divide pixels by 2.083 to get points. At 300 DPI: divide pixels by 4.167.
For most print and document purposes, working in inches or millimeters and converting to points is the simplest approach.
Enter Your Exact Dimensions
Any size from 1x1 inch to 50x50 inches. Drop your PDF, type your dimensions, download. Free and private.
Open Free PDF ResizerFrequently Asked Questions
What is the maximum custom size I can enter?
Width and height can each be up to 3600 points, which is 50 inches (127 cm). The minimum is 72 points (1 inch). This covers everything from business cards to large-format prints.
Can I resize to a non-rectangular shape?
No. PDF pages are always rectangular. You can set any width-to-height ratio, but the page shape is always a rectangle.
How do I resize a PDF to 6x9 for Amazon KDP?
Click Custom, enter 432 for Width and 648 for Height (6 x 72 = 432, 9 x 72 = 648). Click Resize. The resulting PDF matches KDP trim specifications.
What if I need different pages at different custom sizes?
The tool resizes all pages to the same dimensions. For mixed sizes, split the PDF into groups, resize each group separately with different custom values, then merge the groups back together.
