How Much Binding for a Cal King Quilt?

A California king quilt at 102 by 100 inches comes out four inches past the ten-strip line, and that gap is the reason your shopping list says 7/8 yard. Ten strips would have handled a queen. Here is the 428 inch number behind the cut, where the count breaks, and what a border or a bias cut does to it.

The Four Inches That Cost an Extra Strip

Ten strips of 42 inch fabric carry 420 inches. Take off the 24 inch allowance for the closing seam and the four mitred corners and you can bind anything whose width plus length is 198 inches or less. A queen at 90 by 108 lands on 198 exactly. The California king adds to 202. Four inches over, so the eleventh strip is not a rounding decision. Eleven strips cover 219 inches of width plus length, which leaves 17 inches of headroom here. The square king at 216 has only 3.

The Math for a 102 by 100 Inch Top

Perimeter is (102 + 100) × 2 = 404 inches. Use 24 inches of allowance rather than the 12 some charts print, because the diagonal seam where the ends meet eats 10 to 12 and each mitred corner pulls another 2 to 3. That gives 428 inches. Divide by 42 inches of usable width: 428 ÷ 42 = 10.19, so cut 11 strips. Eleven at 2.5 inches is 27.5 inches of yardage, or 0.76 yard. Seven-eighths of a yard runs 31.5 inches, so 4 inches are left to square up a crooked cut.

Cal King Sizes and Their Strip Counts

Drop moves the width by a foot either way, and the strip count goes with it.

The two smallest tops clear ten strips with 12 and 6 inches to spare. Everything from 202 inches of width plus length upward needs the eleventh, and all three of those share one cut.

Strip Width and the 7/8 Yard Line

Width never touches the 428 inches. It decides how much of the 31.5 inches in a 7/8 yard cut you spend, and whether you can drop back an eighth.

A 2.25 inch strip is the quiet saving: 24.75 inches fits inside 27, so the purchase drops to 3/4 yard. Three inch binding is the only width here that costs a full yard, at 3 inches past the eighth.

Borders, Bias, and Scrap Binding

A 2 inch border takes the top to 106 by 104, or 210, and still 11 strips. Six inches reaches 114 by 112, which is 226 and moves the count to 12 strips at 30 inches, still inside 7/8 yard with 1.5 inches to spare. At 10 inches the top is 122 by 120, or 242, and 13 strips at 32.5 inches break the eighth. Bias is its own sum: a 42 inch width yields about 29.7 inches of bias strip at a 45 degree angle, so 428 ÷ 29.7 = 14.4 and you cut 15 strips. That is 37.5 inches, or 1 1/8 yards. Fat quarters will reach the length too, but three of them make 20 joins against 10 for the straight strips.

Frequently Asked Questions