A4 paper page Print HTML page page width set to how much

A4 paper Vertical printing, the width of the HTML page page is set to how much? This problem is we all puzzled, so the online collection, hope to help you

Recently developed the project encountered a Web page printing problem, this is the second problem, print width settings
A dpi (Dot Per Inch) indicator must be used when converting metric length units to screen resolution.
After my careful testing, found that the Web page printing, the default is 96dpi, not the rumored 72dpi
A4 paper size is 210x297mm, 1 inch =25.41mm conversion, that is 8.264x11.688 inch
So, the resolution of A4 paper 96dpi is 794x1123, which is the pixel we need when we make the Web page.
However, the printer is not full-width printing, there will always be a margin, so we must reduce the page margins when making the page.

Here are the pixel sizes for A4 paper that I tested under various margins:
The resolution of the largest element within the page when the print margin is set to 0mm: 794x1123
<div style= "width:794px;height:1123px;border:1px solid #000000;" > </div>

The resolution of the largest element within the page when the print margin is set to 5mm: 756x1086
<div style= "width:756px;height:1086px;border:1px solid #000000;" > </div>

The resolution of the largest element within the page when the print margin is set to 19.05mm: 649x978
<div style= "width:649px;height:978px;border:1px solid #000000;" > </div>
Report:
A4 size of paper: 210x297mm
A3 size of paper: 297x420mm

A4 paper page Print HTML page page width set to how much