For the perfect nightstand, aim for a height that sits level with your mattress...

https://wiki-book.win/index.php/Finding_the_Perfect_Fit:_Matching_Your_Mattress_Height_to_a_60%E2%80%9363_cm_Nightstand

For the perfect nightstand, aim for a height that sits level with your mattress top or about 5 to 10 cm below it. This ensures you can reach your glass of water or lamp comfortably while lying down