Luxury Bedding – What is the Difference between a Down Comforter’s Filling Weight and Fill Power?

Down comforters are one of the nicest items of luxury bedding available. They are light, fluffy, warm, breathable, and make a bed look absolutely inviting. But when you are looking for a new down comforter, be warned, not all down comforters are created equal. You can easily buy something online that won’t meet our expectations when it arrives at your doorstep.

A common question I get about down is, “what’s the difference between filling weight and fill power?” In fact they are very different things. Filling weight is simple to understand: the amount of down and feathers, measured in ounces, inside the comforter. It does not include the weight of the cotton (or whatever fabric) shell that encases the down. Some retailers give the total weight of the comforter, which includes the shell, rather than the filling weight. So when comparing comforters, be sure to distinguish between total weight of the comforter and filling weight.

Fill power (fp) is only a little tricky to understand. Fill power measures the amount of space that an ounce of down occupies. Higher fill power numbers mean that the down clusters expand more and is therefore of higher quality. Quality down starts at about 500fp and goes up to 800 - 900fp.

Fill Power Quality Grading

• Less than 500fp = OK
• 500 - 600fp = good
• 600 - 700fp = great
• Greater than 700fp = amazing

When you are deciding on a new down comforter, budget will be an important factor. Comforters with over 700fp get expensive quickly, and you can expect to pay over a thousand rather than a few hundred. That’s because the down at this high level needs a lot of time/money intensive manual labor to produce. But not to worry, comforters in the 600 – 700fp range are quite excellent and can be had for a very reasonable price.