Tabloid paper size Equivalent A2 paper dimensions in pixels at 300 DPI and 72 DPI respectively are: 4961 pixels x 7016 pixels (print resolution) 1191 pixels x 1648 pixels (screen resolution)
300 dpi = 4,960 x 7,016 px.
Usually a minimum of 300 dpi is absolutely fine. Using a higher dpi is only required if you are doing large format printing such as A2, A1 A0 posters. For these larger posters or a high quality photos then you can use 400-500 dpi, but in most cases 300 dpi will suffice.
Usually, for a quality print, we need about 300 DPI, meaning that an image the size of an A4 paper should count 2480x3507 pixels.
Tabloid paper size
Equivalent A2 paper dimensions in pixels at 300 DPI and 72 DPI respectively are: 4961 pixels x 7016 pixels (print resolution) 1191 pixels x 1648 pixels (screen resolution)
A2 Printing Resolution
The resolution needed to print A2 size images with the best quality is 420 x 594 mm at 300 PPI (pixels per inch).
To produce a photographic quality print at 300dpi resolution you need an image that's 4,800 pixels wide (16 x 300) by 4,200 pixels high (14 x 300).
Printing with A3.
For an image with a resolution of 300 dpi (dots per inch), you will need a size of 3508 x 4961 pixels per inch.
A4 size in pixels at 300 DPI: 2480 x 3508 pixels.
In theory, an A2 size can be displayed or printed in any resolution. For a sharp image, however, a minimum number of pixels is required. The minimum number of pixels for a sharp image is 300 PPI/DPI (2480 x 3508 pixels).
Look for the term "borderless" in the paper size section of the printer settings. A2 Canvas should be 420 x 594 mm, 300 PPI for books, brochures, magazines, 200 -220 PPI is ok for photos. As you have discovered you can resize your image in Photoshop and as Derek said A2 is 420mm x 594mm.
Since every inch contains 300 pixels, that means that your 8.5”x11” file should be: 2550 pixels wide (300 pixels/inch * 8.5 inches) and. 3300 pixels tall (300 pixels/inch * 11 inches)
At 300 pixels per inch (which roughly translates to 300 DPI, or dots per inch, on a printing press), an image will appear sharp and crisp. These are considered to be high resolution, or high-res, images.
What is A3 size in pixels? If you're creating artwork for a poster, or indeed anything that will be printed, you should always create it at 300dpi (dots per inch). This will ensure your design reproduces correctly without any visible pixilation. At 300dpi, A3 artwork (without bleed) should be 3508 x 4961 pixels.
PPI refers to how many pixels per inch there are in a digital image. So, technically, it's PPI until you have a physically printed image, then it becomes DPI and vice versa. However, pixels and dots are pretty much interchangeable. A 300 PPI image will still be a 300 DPI image.
The DPI of a digital image is calculated by dividing the total number of dots wide by the total number of inches wide OR by calculating the total number of dots high by the total number of inches high.
Nowadays, most printers have a resolution of at least 300 DPI or 300 PPI. That means for every square inch of paper, there will be 300 tiny dots of ink. This is more than enough for most printing needs, such as for text or simple graphics.
Resolution for a standard poster starts at around 124 dots per inch (dpi). The best dpi for a poster is 300dpi.
Print & Mount Sizes
The A2 size print measures 42.0 x 59.4cm, 16.53 x 23.39 inches, if mounted 59.4 x 76.6cm, 23.39 x 30.16 inches.
A2 poster size is 594mm x 420mm.