For a comfortable reach, your nightstand should sit level with the top of your...

https://meet-wiki.win/index.php/How_to_Choose_the_Perfect_Nightstand_When_Your_Mattress_Has_a_Significant_Overhang

For a comfortable reach, your nightstand should sit level with the top of your mattress or just 5-10 cm below it. Most UK beds work best with a table height between 55-70 cm