You can print the calendar on A4-size paper. It should fit perfectly.
But if you want to do that, you should adjust printer / page-setting of your browser as follows:
Orientation: Portrait
Header text: empty
Footer text: empty
Margin top: 5 mm
Margin bottom: 5 mm
Margin left: 15 mm
Margin right: 15 mm
If the settings are correct, then you can print the calendar.
You will need exactly 13 sheets of paper.