How to Determine the Warmth of a Down Comforter

Find the fill power of the down comforter on the exterior packaging or on the label attached to the comforter. Fill power measures the amount of cubic inches of down per ounce. Down comforters with a higher fill power in the 500 to 750 range provide more warmth and insulation, because they consist of more down in each down cluster. Such comforters typically appear fluffier.

Determine the type of stitching used to hold the down in place. Baffle or baffle box stitching attaches the front and back of the comforter shell with vertical strips or boxes of material that hold the down in place, preventing clumping and cold spots. Sewn-through down comforters attach the front and back of the shell without additional stitching, which can lead to bunches and thinned-out areas, yielding less warmth than baffled stitching. Baffle-stitched down comforters are more expensive than sewn-through comforters because of the intricate stitching process.

Look for the thread count of the down comforter. Thread count refers to the number of threads per square inch of fabric, determining the quality, texture and durability of the comforter. Down comforters with higher thread counts are warmer, softer, and more breathable, because the threads are closer together, preventing fill from getting out and cold air from seeping in.