Handmade quilts may be heirlooms to pass along for generations, and purchased commercial quilts come in a bewildering array of sizes and styles. Sort your sewing options and simplify your buying by knowing the standard quilt sizes and what those measurements mean.
By the Numbers
Standard mattress sizes determine basic quilt sizes, but there's plenty of room for variety. Most measurements include some kind of a drop -- commonly over both sides and the bottom, or foot of the bed. A crib mattress gets a short drop. The shortest drop for normal mattresses is about 12 inches. So short-drop quilts measure roughly:
Crib: 36 by 54
Twin: 63 by 87
Twin XL: 63 by 92
Full: 78 by 87
Queen: 84 by 92
King: 102 by 92
California king: 96 by 96
A mattress used to average about 8 to 10 inches in thickness, but luxury mattresses now may include pillow-tops and other embellishments that raise the height of the mattress to 14 to 18 inches. This won't affect a crib quilt, but a 16-inch tall mattress needs a bigger drop to cover the mattress and sheets. So, for that height, quilts would measure:
Twin: 71 by 91 inches
Twin XL: 71 by 96
Full: 86 by 91
Queen: 92 by 96
King: 110 by 96
California king: 104 by 100
The look you want for the bed -- and the particular bed itself -- should determine how you calculate the correct quilt size. A platform bed has only a mattress, no box spring, so the quilt drop will be fairly short. For a quilt that drops to the floor -- actually to within about 1/2 inch of the floor -- measure the bed height from the floor with mattress, box spring and bedding.
A quilt that will tuck under and then fold over the bed pillows is going to be longer -- most quilts tuck slightly under the edge of the pillows. A bed with a tailored skirt or a dust ruffle looks best when the quilt drops about 3 inches over the top of the dust ruffle.
A foot board that hugs the mattress needs a quilt without a bottom drop to avoid bunching. A daybed needs a drop on one side only, if it is positioned against a wall. And a quilt with a central figure or medallion should be sized so the dominant design rests at the center of the bed.
A small decorative quilt draped over the arm of the sofa or the back of your favorite reading chair is an invitation to snuggle under it on a chilly afternoon. Lap quilts are used for decoration, wheelchair warmth, wall hangings, kid comforters and crib quilts. The size varies -- there is no standard. You buy or make the quilt to fit the purpose. A 34-by-44-inch quilt approximates a neat size for use in a wheelchair. About 42 by 60 inches is a nice couch cozy. A very generous lap quilt could range from 52 inches or more wide by 76 inches or less long, and 36 by 36 inches is large enough for a child to use as a portable blankie.