Setting ruler for A4 format - Visual Studio Code

I'm wondering which is the max number of characters which I could write in a C++ sheet in Visual Studio Code (font size 14) so that, when I print it on an A4 sheet, it respects the format which I see on my screen.

{
    "C_Cpp.updateChannel": "Insiders",
    "editor.rulers": [
    Is 80 too small?
    ]
}