How much fabric does a throw quilt really take? A full plan, start to finish
Photo: Olga Ferina on Unsplash
Most quilt patterns print a fabric list, and most of the time it’s right. The trouble starts when you change something: you make the quilt a little bigger, swap the backing for a wide-back fabric, or decide to use your stash instead of a fat-quarter bundle. Then the list stops matching, and you’re doing fraction math in the middle of the fabric shop.
This guide walks through one quilt from beginning to end so you can see where every number comes from. Once you’ve seen it done once, you can do it for any quilt.
The quilt
A simple throw built from 120 squares cut at 5½ inches (5 inches finished), set 10 across and 12 down. That gives a center of 50 × 60 inches. A 5-inch border brings it to 60 × 70 inches, a comfortable couch throw.
Step 1: the squares
Each square is cut at 5½ inches, so the seam allowance is already included. On 42-inch usable fabric you get 7 squares across one strip (7 × 5½ = 38½ inches). For 120 squares you need 120 ÷ 7 = 17.1, so 18 strips. Eighteen strips at 5½ inches is 99 inches of fabric, which rounds up to 2¾ yards if it all came from one fabric.
Of course a scrappy quilt doesn’t come from one fabric. If you’re using fat quarters, each one gives you 3 strips of 5½ inches across its 18-inch side, with 3 squares per strip on the 21-inch side: 9 squares per fat quarter. That’s 14 fat quarters for 120 squares, with a few spare. The fabric cutting calculator does this for any piece size.
Step 2: the border
The center measures 50 × 60 inches (measure yours through the middle, it will be slightly off). A 5-inch finished border is cut 5½ inches wide.
- Side borders: 2 × 60 = 120 inches
- Top and bottom: 2 × (50 + 10) = 120 inches
- Total: 240 inches, which is 6 strips of 42 inches
Six strips at 5½ inches is 33 inches, which rounds up to 1 yard. The border calculator shows each length.
Step 3: the backing
This is the step that surprises people. The finished top is 60 × 70 inches. Most longarm quilters want 4 inches extra on every side, so the back has to be 68 × 78 inches.
You can’t get 68 inches from one width of 42-inch fabric, so the back is two panels sewn together. There are two ways to lay them:
- Seams running top to bottom: two panels, each 78 inches long = 156 inches = 4⅜ yards.
- Seams running side to side: two panels, each 68 inches long = 136 inches = 3⅞ yards.
Same quilt, half a yard apart. Most people default to the first one because it feels natural, and buy more than they need. The backing calculator always shows you both.
A third option is 108-inch wide backing: the back fits in one piece, and you buy 68 inches of length, which rounds up to 2 yards. Wide backing costs more per yard, but at roughly half the yardage and no seam to sew, it’s often cheaper overall.
Step 4: batting
The batting needs to cover the same 68 × 78 inches. A crib package (45 × 60) is too small. A twin package (72 × 90) covers it with room to spare. The batting calculator checks this against the common package sizes.
Step 5: binding
The perimeter of a 60 × 70 quilt is 260 inches. Add 10 inches for the corners and the join: 270 inches. At 42 inches per strip that’s 6.4, so 7 strips. Seven strips at 2½ inches is 17½ inches, which rounds up to ½ yard.
The full shopping list
| Part | Amount |
|---|---|
| Squares | 14 fat quarters (or 2¾ yd of one print) |
| Border | 1 yd |
| Backing | 3⅞ yd of 42″ cotton, or 2 yd of 108″ wide |
| Batting | Twin package (72 × 90″) |
| Binding | ½ yd |
Where people come up short
Shrinkage. If you prewash, cotton can shrink 3 to 5 percent. That’s an extra 2 inches on a 42-inch width, which can push a two-panel back into needing three. Measure the washed fabric and use that width.
Straightening the edge. The first cut on any fabric is a clean-up cut. If the fabric was cut crooked at the shop, you can lose an inch or two before you cut a single strip.
Directional prints. A print with an up and a down limits which way you can run the backing seams. Check before you pick the cheaper direction.
Changing your mind. If there’s any chance the quilt grows a second border, buy the border fabric generously now. Matching it later is the hardest part.
Every number above came from the same calculators that are on this site, and each one shows its working, so you can check it against your own pattern.