One each side, level with the mattress.
A nightstand does one job: put a glass, a book and a lamp within reach.
A pair
Give a couple's bed two nightstands, one each side, 0 to 4 inches off the mattress. Where a side has under 20 inches, a nightstand and a wall sconce share the job. A mismatched pair looks right when the tops are the same height.
Height
The top sits level with the mattress, or up to 2 inches above it: 24 to 27 inches for most beds, 24 to 30 with a tall mattress stack. You should reach a glass without sitting up.
The bed wall
| Bed | Wall width |
|---|---|
| King | 124″ (136″ for 30″ each side) |
| Queen | 108″ (120″ ideal) |
| Full | 102″ |
| Twin | 62″ |
Each includes 24 inches of floor beside the bed. When the wall is short, the next size down keeps the bedside open. The headboard stands 48 to 60 inches tall against a solid wall.
Blank Space chooses the bed size from the bed wall, then adds a nightstand on each side.