Chandelier and pendant sizing

The oldest rule in the trade still works: add the room's length and width in feet, and the answer in inches is roughly the right fixture diameter. A twelve by fourteen room takes something around twenty-six inches across. For height, allow two and a half to three inches of fixture for every foot of ceiling, so a nine foot ceiling suits a fixture roughly twenty-two to twenty-seven inches tall.

Over a dining table the room dimensions stop mattering and the table takes over. Aim for between half and two thirds of the table's width, and never go wider than the table minus twelve inches, or people at the ends will knock their heads reaching across. Hang it thirty to thirty-six inches above the table top at an eight foot ceiling, and add roughly three inches for every additional foot of ceiling height.

These are proportion rules, not physics, and a good eye beats them. An airy fixture of thin metal and glass can go noticeably larger than the arithmetic suggests without dominating a room, while a solid drum shade at the same diameter will feel oppressive. Long tables and two-storey foyers usually want a linear fixture or a matched pair rather than one enormous chandelier.