Resize Image to A3 Size (297 x 420 mm)

A3 paper measures 297 x 420 mm. At 300 DPI, the resolution needed for clean printing, that works out to 3508 x 4961 pixels. Upload your image below and crop it to the A3 ratio so it fills the page without stretching.

A3 Size in Pixels at Different DPI

72 DPI	842 x 1191 pixels (screen only)
150 DPI	1754 x 2480 pixels
300 DPI	3508 x 4961 pixels (recommended for print)
600 DPI	7016 x 9921 pixels

About A3 Size

Printers work in dots per inch, not pixels, so a file sized for the screen is rarely ready for paper. Preparing the image at 3508 x 4961 pixels means the printer has a real 300 DPI of detail across the full A3 sheet rather than upscaling a smaller file and producing soft edges.

How to Resize an Image to A3 Size

Click Upload File and choose a JPG or PNG image.
Drag and scale the crop box over the part of the picture you want to keep.
Click Download to save the image at 3508 x 4961 pixels, the 300 DPI equivalent of A3 Size.
Need a different DPI? Use Manual Resize and enter the values from the table above.

Frequently Asked Questions

What size is A3 in pixels?

At 300 DPI A3 is 3508 x 4961 pixels. At 150 DPI it is 1754 x 2480, and at 72 DPI it is 842 x 1191.

What DPI should I use for A3 printing?

300 DPI is the standard for photo and document printing. 150 DPI is acceptable for large posters viewed from a distance, and 72 DPI is screen only.

Related Print and Photo Sizes