The golden rule for nightstands is all about comfort. Ideally, aim for the top...

https://www.start-bookmarks.win/for-the-most-comfortable-reach-your-nightstand-should-sit-level-with-your

The golden rule for nightstands is all about comfort. Ideally, aim for the top of your bedside table to sit 5 to 10 cm below the top of your mattress. This makes reaching for your phone or a glass of water feel natural rather than a stretch