Cushion sizes vary widely to accommodate different furniture and personal preferences. Common sizes include 18x18 inches, 20x20 inches, and 24x24 inches for square cushions, while rectangular options often measure 12x20 inches or 14x24 inches. These dimensions help ensure that cushions fit well on sofas, chairs, and beds. When selecting a cushion size, consider the intended use and the space available. Larger cushions can provide more support and comfort, while smaller ones may be better for decorative purposes. Always measure your furniture to find the best fit for your home decor.