Ideal Lamp Height
A bedside table lamp should not be too large or too small, but a happy medium. The size of your lamp should be based upon the size of the bedside table it sits upon and the height of the headboard. If your nightstand is 24 to 30 inches tall, the ideal height for a lamp is 27 to 32 inches tall, advises the website William Miller Design.
Proportion and Balance
If you have a very large, tall bed and bedside tables, you need a lamp that is larger in scale for the most visually appealing look. If you have a smaller bed and nightstands, a smaller lamp is more appropriate. If your nightstands are much shorter than your bed, use taller lamps to even the scale; if they are taller than the bed, use shorter lamps.
Keep the size of the furnishings in mind when you choose the lamp for a pleasing look.