Fat Eighth Size Guide: Pieces, Yardage and How Many for a Quilt
A fat eighth is one piece of about 9 x 21 inches, about 189 square inches or 0.125 yard of fabric. Sewn as simple patchwork it covers about 81 square inches, so a 50 x 65 inch throw top needs about 41 of them and a queen top about 106.
Precuts are bundles of fabric cut to a standard size, usually one or two pieces of every print in a collection. A fat eighth is a single piece of 9 x 21 inches. Other names: F8.
| Piece size | 9 x 21 in |
|---|---|
| Pieces | 1 |
| Total fabric | 189 sq in |
| Yardage equivalent | about 0.125 yd |
| Finished patchwork coverage | about 81 sq in per cut |
| Notes | Fat Quarter Shop cuts 9 x 21. Some shops cut about 11 x 18 instead. |
Cut into 5 inch squares that finish at 4 1/2 inches, four of them make a 9 inch finished block.
How many fat eighths do you need for each quilt size?
Counts assume the whole top is made from this precut, with the piece cut into 5 inch squares that finish at 4 1/2 inches. Add background fabric, sashing or borders and you need fewer. The table below covers every standard quilt size: a 50 x 65 inch throw top takes about 41 of them and a queen about 106.
| Quilt | Top size (in) | Top area (sq in) | Fat Eighths |
|---|---|---|---|
| Baby | 40 x 40 | 1,600 | 20 |
| Crib | 36 x 52 | 1,872 | 24 |
| Lap | 45 x 60 | 2,700 | 34 |
| Throw | 50 x 65 | 3,250 | 41 |
| Twin | 68 x 90 | 6,120 | 76 |
| Twin XL | 68 x 95 | 6,460 | 80 |
| Full / Double | 83 x 90 | 7,470 | 93 |
| Queen | 90 x 95 | 8,550 | 106 |
| King | 106 x 95 | 10,070 | 125 |
| California King | 102 x 99 | 10,098 | 125 |
What can you cut from a fat eighth?
These are the most pieces of each common size you can cut from one cut, rotating the cut where that fits more. The first row is the smallest cut: one cut yields 24 pieces at 2 1/2 in squares (mini charm size).
| Cut size | Pieces |
|---|---|
| 2 1/2 in squares (mini charm size) | 24 |
| 5 in squares (charm size) | 4 |
| 2 1/2 x 21 in strips | 3 |
| 3 1/2 x 6 1/2 in rectangles | 6 |
Measure before you cut
Many precuts have pinked (zigzag) edges. Decide whether you measure from the peaks or the valleys of the zigzag and keep it consistent, or your blocks will not match.
Precut-friendly quilting tools
Moda Bella Solids White Layer Cake
Under $50A layer cake of Bella Solids white, a clean background for pairing with printed precuts.
Check price
Olfa 17 x 17 Rotating Cutting Mat RM-17S
Under $250Trim squares and HSTs on all sides by turning the mat instead of the fabric.
Check price
Bloc Loc Half-Square Triangle Ruler Set #2
Under $100Precise trimming for half square triangles made from charm squares and layer cakes.
Check pricePrices change often, so confirm on Amazon. As an Amazon Associate we earn from qualifying purchases.
Precuts supply the quilt top only. A 50 x 65 inch throw still needs 3 1/4 yards of 42 inch backing and 7 strips of binding, neither of which comes out of the pack, so add both to the shopping list before you start sewing.
How does a fat eighth compare with other precuts?
The table below compares every common precut by fabric content: this one holds 189 square inches, about 0.125 yards, against 4,200 for a layer cake and 1,050 for a charm pack.
| Precut | Piece size (in) | Pieces | Yards equivalent | Finished coverage (sq in) |
|---|---|---|---|---|
| Mini Charm Pack | 2 1/2 x 2 1/2 | 42 | 0.17 | 168 |
| Charm Pack | 5 x 5 | 42 | 0.69 | 851 |
| Layer Cake | 10 x 10 | 42 | 2.78 | 3,791 |
| Jelly Roll | 2 1/2 x 42 | 40 | 2.78 | 3,200 |
| Honey Bun | 1 1/2 x 42 | 40 | 1.67 | 1,600 |
| Dessert Roll | 5 x 42 | 20 | 2.78 | 3,600 |
| Turnover | 6 x 6 | 80 | 0.95 | 1,000 |
| Fat Quarter | 18 x 21 | 1 | 0.25 | 243 |
| Fat Eighth | 9 x 21 | 1 | 0.125 | 81 |
| Half Yard Cut | 18 x 44 | 1 | 0.5 | 486 |
Frequently asked questions
How many pieces are in a fat eighth?
A fat eighth is a single piece of about 9 x 21 inches. Fat Quarter Shop cuts 9 x 21. Some shops cut about 11 x 18 instead. Always check the label, because counts and exact sizes vary by manufacturer and collection, and some pieces are pinked at the edges, which slightly reduces the usable size.
How many fat eighths do I need for a throw quilt?
A 50 x 65 inch throw top is 3,250 square inches. With the piece cut into 5 inch squares that finish at 4 1/2 inches, one cut covers about 81 square inches, so plan about 41. That is for the patchwork only: sashing, borders, backing and binding need separate yardage.
How many fat eighths do I need for a queen quilt?
A 90 x 95 inch queen top is 8,550 square inches, so you would need about 106 at roughly 81 square inches each. Many quilters stretch fewer precuts by adding a solid background fabric, wide sashing or a border, which also makes the prints stand out.
How much yardage is a fat eighth?
A fat eighth holds about 189 square inches of fabric, which is roughly 0.125 yard of 42 inch cotton by area. Precuts give far more print variety than one yard of a single fabric, which is why they cost more per square inch. The trade-off is less flexibility in what you can cut.
Do I need to prewash a fat eighth?
Most quilters do not. Precut edges fray and distort in the wash, pinked edges lose their shape, and a 9 inch piece has no spare size to give away, since cotton can lose 1 to 2 inches per yard. If you are worried about a saturated red or navy bleeding, test a single piece in hot water with a color catcher rather than washing the whole pack.
Is a fat eighth cheaper than buying yardage?
Per square inch, no. It holds about 189 square inches, roughly 0.125 yards, and costs more than the same yardage of a single print because you are paying for the variety and for the cutting. What you get back is time at the cutting mat, coordinated prints from one collection, and no leftover yards of a fabric you only wanted a little of.
What can I make with one fat eighth?
One cut covers about 81 square inches of finished patchwork, which suits a table runner, pillow, pot holders, a mini quilt or a pieced tote. Combined with background fabric it can become the center of a baby quilt; a 40 x 40 inch baby top made only from these needs about 20.
Sources
- Moda Fabrics (United Notions) precut definitions: Layer Cake, Charm Pack, Jelly Roll and Mini Charm sizes and counts
- Manufacturer precut labels from Robert Kaufman, Riley Blake and Art Gallery Fabrics (piece counts vary by collection)
- Standard quilt top sizes from the site quilt size chart, used for every per-quilt count
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.
