For a comfortable bedroom, your nightstand should sit between 55 and 70...

https://www.blaze-bookmarks.win/the-golden-rule-for-bedside-tables-is-comfort-and-accessibility-aim-for-a

For a comfortable bedroom, your nightstand should sit between 55 and 70 centimetres high. The golden rule is to keep the tabletop about 5 to 10 centimetres below your mattress top