Precut Fabric Calculator: How Many Fat Quarters, Charm Packs, Layer Cakes and Jelly Rolls
A 90 x 95 inch queen quilt pieced from 4 1/2 inch finished squares needs about 11 charm packs, 3 layer cakes or 36 fat quarters. A 50 x 65 inch throw needs about 4 charm packs, 1 layer cake or 14 fat quarters.
Precuts are fabric sold already cut into squares, strips or fat quarters, usually a whole collection of coordinated prints in one bundle. Enter the quilt size and the finished size of each patch. The calculator counts how many of each precut you need, both by whole patches and by fabric area, and tells you which precuts are too small for your patch.
Your quilt
Your results
Patches to cut
10,556 sq in of fabric, about 7 7/8 yards
| Precut | By patches | By area |
|---|---|---|
| Charm Pack | 11 | 11 |
| Layer Cake | 3 | 3 |
| Jelly Roll | Too small | 3 |
| Fat Quarter | 36 | 32 |
| Fat Eighth | 106 | 63 |
| Mini Charm Pack | Too small | 41 |
"Too small" means the precut piece is narrower than your cut patch.
Cutting and piecing tools for a big precut quilt
Dozens of fat quarters or several layer cakes is a lot of repeat cutting and hundreds of seams. These carry that workload.
AccuQuilt GO! Big Electric Fabric Cutter Starter Set
$699.99An electric die cutter that cuts up to six layers, so a stack of fat quarters becomes patches in minutes.
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Olfa 35 x 70 Continuous Grid Connecting Rotary Mat Set
$209.99A 35 x 70 in surface for laying out and cutting many precuts at once.
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Juki TL-2010Q High-Speed Sewing and Quilting Machine
$1,199.00A 1,500 SPM straight-stitch machine for piecing a queen top quickly and accurately.
Check pricePrices change often, so confirm on Amazon. As an Amazon Associate we earn from qualifying purchases.
Tools for a throw or baby quilt from precuts
For a smaller quilt, a manual die cutter or a rotating mat plus a reliable machine is the sweet spot.
AccuQuilt GO! Fabric Cutter Starter Set
$329.99A folding die cutter with a value die that includes 4 1/2 and 2 1/2 in squares.
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Olfa 17 x 17 Rotating Cutting Mat RM-17S
$100.98Trim charm squares and layer cake squares without moving the fabric.
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Brother CS7000X Computerized Sewing and Quilting Machine
$279.99A computerized machine with a wide table and quilting accessories at a beginner price.
Check pricePrices change often, so confirm on Amazon. As an Amazon Associate we earn from qualifying purchases.
How do you calculate how many precuts you need for a quilt?
There are two honest ways to count, and the calculator shows both. Counting by whole patches respects the shape of each precut. Counting by area assumes every square inch gets used, which is closer to a scrappy quilt with pieces of many sizes. Here is the math for a 90 x 95 inch queen made of 4 1/2 inch finished squares.
- Count the patches. Quilt area / patch area, rounded up: 8,550 / 20.25 = 423 patches.
- Add seam allowance. Each patch is cut 1/2 inch larger, so 5 inches square.
- Patches per precut. A 5 inch charm square gives 1. A 10 inch layer cake square gives 4, so 168 per 42-square cake. A 18 x 21 inch fat quarter gives 3 across and 4 down, 12 patches.
- Divide and round up. 423 / 42 = 11 charm packs. 423 / 168 = 3 layer cakes. 423 / 12 = 36 fat quarters.
The area method starts from the same place. Cut size squared over finished size squared is the seam factor: (5 / 4.5) squared is about 1.235, meaning seams use 23 percent more fabric than the finished top shows. That gives 10,556 square inches of cut fabric. A charm pack holds 1,050 square inches, so 10.05 rounds up to 11 packs. Fat quarters and fat eighths lose 10 percent to straightening by default, so a fat quarter counts as 340.2 usable square inches and the queen needs 32 by area.
When the two counts disagree, trust the higher one. For fat quarters, the patch count is higher here because 5 inch squares leave a 3 inch strip along one side of every fat quarter. Those strips are great for binding or sashing, but they will not make more 5 inch squares.
What sizes are precut fabrics?
Sizes and counts below are the most common published figures. Counts vary by manufacturer and collection, so check the label: some charm packs have 40 squares instead of 42. Yard equivalents use 36 x 42 inches per yard and ignore waste.
| Precut | Piece size | Pieces | Total area | About |
|---|---|---|---|---|
| Mini Charm Pack | 2 1/2 x 2 1/2 in | 42 | 262.5 sq in | 1/8 yd |
| Charm Pack | 5 x 5 in | 42 | 1,050 sq in | 3/4 yd |
| Layer Cake | 10 x 10 in | 42 | 4,200 sq in | 2 3/4 yd |
| Jelly Roll | 2 1/2 x 42 in | 40 | 4,200 sq in | 2 3/4 yd |
| Honey Bun | 1 1/2 x 42 in | 40 | 2,520 sq in | 1 5/8 yd |
| Dessert Roll | 5 x 42 in | 20 | 4,200 sq in | 2 3/4 yd |
| Turnover | 6 x 6 in (half square) | 80 | 1,440 sq in | 1 yd |
| Fat Quarter | 18 x 21 in | 1 | 378 sq in | 1/4 yd |
| Fat Eighth | 9 x 21 in | 1 | 189 sq in | 1/8 yd |
| Half Yard Cut | 18 x 44 in | 1 | 792 sq in | 1/2 yd |
Our precut fabric chart has more detail on each type, and the precuts section has project ideas by precut.
How many precuts does each quilt size need?
Every row uses 4 1/2 inch finished patches, the size a whole charm square makes, and counts whole patches. Sizes follow our quilt size chart.
| Quilt | Size (in) | Patches | Charm packs | Layer cakes | Fat quarters | Fat eighths |
|---|---|---|---|---|---|---|
| Mini / Wall Hanging | 24 x 24 | 29 | 1 | 1 | 3 | 8 |
| Baby | 40 x 40 | 80 | 2 | 1 | 7 | 20 |
| Crib | 36 x 52 | 93 | 3 | 1 | 8 | 24 |
| Lap | 45 x 60 | 134 | 4 | 1 | 12 | 34 |
| Throw | 50 x 65 | 161 | 4 | 1 | 14 | 41 |
| Twin | 68 x 90 | 303 | 8 | 2 | 26 | 76 |
| Twin XL | 68 x 95 | 320 | 8 | 2 | 27 | 80 |
| Full / Double | 83 x 90 | 369 | 9 | 3 | 31 | 93 |
| Queen | 90 x 95 | 423 | 11 | 3 | 36 | 106 |
| King | 106 x 95 | 498 | 12 | 3 | 42 | 125 |
| California King | 102 x 99 | 499 | 12 | 3 | 42 | 125 |
How does patch size change which precuts work?
A precut can only make patches smaller than itself. The table shows the queen at five finished patch sizes. As patches shrink, seams take a bigger share of the fabric, and more precuts become usable.
| Finished patch | Cut | Seam factor | Charm packs | Layer cakes | Jelly rolls | Fat quarters |
|---|---|---|---|---|---|---|
| 2 in | 2 1/2 in | 1.56 | 13 | 4 | 4 | 39 |
| 2 1/2 in | 3 in | 1.44 | 33 | 4 | Too small | 33 |
| 3 1/2 in | 4 in | 1.31 | 17 | 5 | Too small | 35 |
| 4 1/2 in | 5 in | 1.23 | 11 | 3 | Too small | 36 |
| 9 1/2 in | 10 in | 1.11 | Too small | 3 | Too small | 48 |
Assumptions behind these numbers
Patches are squares cut 1/2 inch larger than finished. Factory precuts are used as cut, with no waste. Fat quarters are 18 x 21 inches and fat eighths 9 x 21 inches, both with your waste allowance by area. Jelly roll strips are counted at 42 inches. Real quilts add sashing, borders and background fabric, which usually come from yardage.
Should you prewash precut fabric?
Most quilters do not prewash small precuts. Charm squares, layer cakes and jelly roll strips are cut to exact sizes, and washing makes them fray and shrink, so a 5 inch square can come out noticeably smaller and no longer finish at 4 1/2 inches. Fat quarters are large enough to prewash if you want to, as long as you allow for shrinkage when you cut.
If you worry about dark or saturated colors bleeding, wash the finished quilt in cool water with a dye-trapping laundry sheet instead. Test a strongly colored fabric first by wetting a scrap and pressing it on a white cloth. The waste allowance in the calculator covers straightening and trimming, not shrinkage from prewashing.
Are fat quarters or layer cakes better for a first quilt?
Layer cakes are the gentlest start: 42 coordinated squares, already cut straight, that you can sew together whole or cut into quarters. There is almost no measuring. Fat quarters give bigger pieces and more flexibility, since an 18 x 21 inch rectangle can make large blocks a layer cake cannot, but they need straightening and more cutting.
Charm packs are small and inexpensive, perfect for a baby quilt or trying a collection before committing to yardage. Jelly rolls suit strip-pieced designs, and they pair naturally with a strip cutter die. Whatever you choose, plan background, border and binding fabric separately with the quilt fabric yardage calculator. For triangle units from charm squares, the half square triangle calculator shows which sizes a 5 inch square can make.
Frequently asked questions
How many fat quarters do I need for a queen quilt?
For a 90 x 95 inch queen made of 4 1/2 inch finished squares, you need 423 squares cut at 5 inches. A 18 x 21 inch fat quarter yields 12 of them, so plan on 36 fat quarters. Measured by area alone with 10 percent waste it is 32, but whole squares leave strips unused, so the patch count is the safer number.
How many charm packs make a throw quilt?
A 50 x 65 inch throw made entirely from 5 inch charm squares, which finish at 4 1/2 inches, takes 161 squares. At 42 squares per pack that is 4 charm packs. Charm counts vary by collection, and some packs have 40 squares, so check the pack and consider adding a border to stretch fewer packs.
How many layer cakes do I need for a queen quilt?
A layer cake has 42 squares 10 inches wide, about 2 3/4 yards of fabric. Cut into 5 inch patches, each square gives 4, or 168 per cake, so a queen of 4 1/2 inch finished squares needs 3 layer cakes. Using the squares whole as 9 1/2 inch finished blocks, a queen needs about 3 cakes.
What can I make with one jelly roll?
A jelly roll has 40 strips 2 1/2 inches wide by about 42 inches, roughly 2 3/4 yards of fabric. Jelly rolls suit strip piecing and patches that finish at 2 inches or less. A 50 x 65 inch throw made of 2 inch finished squares needs about 2 jelly rolls. Jelly roll race quilts, which sew strips end to end, use one roll for a lap-size top.
Do precuts have seam allowance included?
Precuts are the cut size, so seam allowance comes out of them. A 5 inch charm square finishes at 4 1/2 inches after 1/4 inch seams on each side, and a 10 inch layer cake square finishes at 9 1/2. Many precuts have pinked edges; some quilters measure to the outer points and some to the inner valleys, which can shift a finished block by about 1/8 inch.
Are precuts cheaper than yardage?
Usually not by the square inch. You pay for the cutting and the variety: a charm pack gives dozens of coordinated prints in about 3/4 yard of fabric, which would cost far more to assemble from separate cuts. Precuts save the most when a quilt wants maximum variety. For large areas of one fabric, like backgrounds and borders, yardage is cheaper.
How we research: we compare manufacturer specifications, owner manuals, published standards and recurring themes in verified owner reviews. We do not test products in person, and this is researched guidance, not professional advice. Follow your machine manual and pattern, and take care with rotary cutters, hot irons and needles. As an Amazon Associate we earn from qualifying purchases.