Depending on your MacBook model, the top of your screen will be positioned approximately at the following heights above the desktop:
MacBook / 2015 and later: h = 33 cm / 13 inch
MacBook Air: h = 33 cm / 13 inch
MacBook Pro 13-inch / 2012 and later: h = 38 cm / 15 inch
MacBook Pro 14-inch / 2021: h = 39 cm / 15 inch
MacBook Pro 15-inch / 2012 and later: h = 43 cm / 17 inch
MacBook Pro 16-inch / 2019: h = 43 cm / 17 inch
MacBook Pro 16-inch / 2021: h = 44 cm / 17 inch