Definitions for "FILL POWER"
Keywords:  loft, ounce, cubic, warmth, warmer
Refers to the volume of down and the quality of the comforter. Read more about comforters.
The measurement in cubic inches that one ounce of down will fill when placed in a glass tube and allowed to loft for up to 3 days.
In down bedding, the measurement in cubic inches than a single ounce of down will fill. Quality down comforters have a fill power between 550 and 650 cubic inches; the higher the fill power number, the warmer the comforter.