Does anybody know what are the minimum A4 margins (both landscape and portrait) which will allow to print the content on the most desktop printers out there?

I'm under the impression it's 5 mm, based on my inkjet printers experience. Unless you have a borderless enabled printer then you can print border to border.

So if I set every margin to 5 mm most people will be able to print the content on their desktop printer? Anyone else?

Hard to say, it's different for each printer.

My good old HP deskjet 520 has larger margins, about 7 mm for left, top and right. For bottom it's even larger, 17 mm. Specifically that large bottom margin is rather annyoing from time to time.

Thanks for the input.

Hi you can always do a print test to find the max area for print.

Place a few rectangles of different colour on top of each other and copy them to each side.Then looking at the print you can see where your margin begins. Doing it this way (before reading topic I estimated a4 to be 5mm on each side. This is with an epson injet.

I used the align function for placing on the borders and kept each rectangle the same size. Using grid view also helped a lot.

Does anyone know margins for a4 8.5 x 11? Until I get some cheap paper I cant test.

Edit. You can also use print preview to show the paper margins. This would seem the best way.
It works when I use an epson r285 but dosnt appear when I use the d120 model.

Id now put safe margins for a4 at 3.5mm. Maybe as low as 3mm.

The reason I said "most desktop printers out there" is that I can't test everybody's printers I prepared an illustration I described as printable and I wouldn't want it to be cut out by margins on some contemporary desktop printers.