Converting a PDF to JPG produces a pixel size based on the page dimensions and the DPI you select. The search phrase pdf page size in pixels asks exactly that: how many pixels wide and tall your converted page will be at a given DPI. Here are the pixel dimensions for A4 and US Letter at 72, 150, and 300 DPI, plus the formula to calculate any size.
How PDF Page Size is Measured
PDF documents measure page dimensions in points. One point equals 1/72 of an inch, so 72 points make one inch. This is the same unit used in typography. To convert points to inches, divide by 72. To get pixels, multiply the inch measurement by your DPI.
The formula is: pixels = (points / 72) x DPI. For example, a page that is 72 points wide at 72 DPI becomes (72 / 72) x 72 = 72 pixels wide. At 300 DPI, the same page becomes (72 / 72) x 300 = 300 pixels wide.
A4 Page Size in Points and Inches
A4 paper is defined as 210 x 297 millimeters. In PDF points, that equals 595 x 842. Check the math: 210 mm is about a few inches, and that measurement x 72 points per inch = 595 points. Similarly, 297 mm is about a few inches, and that x 72 = 842 points.
To calculate a4 size in pixels 300 dpi directly: (595 / 72) x 300 = 2480 pixels wide, and (842 / 72) x 300 = 3508 pixels tall.
Letter Page Size in Points and Inches
US Letter paper measures 8.5 x 11 inches. In points, that is 8.5 x 72 = 612 points wide, and 11 x 72 = 792 points tall. The letter size in pixels at any DPI is therefore (612 / 72) x DPI for width and (792 / 72) x DPI for height.
At 300 DPI, a Letter page becomes 2550 x 3300 pixels. At 150 DPI, it becomes 1275 x 1650 pixels.
Pixel Dimensions Table for A4 and Letter
These are the exact pixel dimensions for A4 and Letter at three common DPI values. Use them when you convert a PDF page to a JPG image.
A4 Dimensions
- 72 DPI: 595 x 842 pixels
- 150 DPI: 1240 x 1754 pixels
- 300 DPI: 2480 x 3508 pixels
US Letter Dimensions
- 72 DPI: 612 x 792 pixels
- 150 DPI: 1275 x 1650 pixels
- 300 DPI: 2550 x 3300 pixels
How to Calculate Any DPI Value
For a DPI not listed here, calculate it yourself. Follow these steps:
- Find the page size in points. A4 is 595 x 842. Letter is 612 x 792.
- Divide the width in points by 72 to get inches.
- Multiply the inches by the DPI you want. This gives the pixel width.
- Repeat for the height.
For a4 150 dpi pixels: (595 / 72) x 150 = 1240 pixels wide; (842 / 72) x 150 = 1754 pixels tall. The same method works for Letter or any other page size when you know its dimensions in points.
How DPI Affects Pixel Count
Doubling the DPI doubles the pixel width and doubles the pixel height. The total number of pixels becomes four times larger. A4 at 72 DPI has 595 x 842 pixels. At 150 DPI it has 1240 x 1754, roughly four times more. At 300 DPI it has 2480 x 3508, many times more than at 72 DPI.
Choose your DPI carefully. Higher DPI produces larger file sizes and more detail, but takes more time to process and more storage space.
Using the Site's PDF to JPG Tool
The PDF to JPG converter at pdftojpgconverter.net renders pages at 150 DPI by default. An A4 page becomes 1240 x 1754 pixels, and a Letter page becomes 1275 x 1650 pixels. Expect those dimensions from a standard conversion without changing any settings.
To get a different pixel size, adjust the DPI in your conversion settings, or use the formula above to predict the result.