Style gets all the attention. But visit a room where every piece is stylistically perfect and poorly proportioned, and you will immediately feel the discomfort.
The Room-to-Furniture Ratio
Living room furniture should occupy roughly 35% of the floor area. This leaves ample circulation and visual breathing room. A room filled to capacity feels stressful, not luxurious.
Coffee Table Sizing
The coffee table should be roughly half the length of the sofa it sits in front of, and within 14-18 inches of the sofa edge. The height should be within 2 inches of the sofa seat height.
Dining Table Sizing
Each person at a dining table needs roughly 24 inches of width and 15-18 inches of depth. Allow at least 36 inches of clearance between the table edge and the nearest wall for pulled-out chairs.