How Many Fat Quarters Do I Need for a Quilt?
Count the pieces one fat quarter gives, divide your total by it and round up. Chart of squares per fat quarter, plus worked examples for two throw quilts.
https://needlenook.app/learn/how-many-fat-quarters-for-a-quilt
A 50" x 60" (127 x 152.4 cm) throw of 120 squares that finish at 5" needs 14 fat quarters. The arithmetic: one fat quarter gives 9 squares cut at 5 1/2", and 120 ÷ 9 = 13.3, rounded up. The rule is the same for any piece: divide the pieces the quilt needs by the pieces one fat quarter gives, then round up.
The assumption behind that count is the usable size. A fat quarter is sold as 18" x 22" (45.7 x 55.9 cm); after the selvage is trimmed, this guide plans on 18" x 20" (45.7 x 50.8 cm). The sections below give the chart behind that number, a second example, and the cases where a yardage pattern cannot be cut from fat quarters at all. Check the usable size of your own fat quarters before cutting.
Key points
- A fat quarter is a one-yard cut (36" x 44") divided into four, so it measures 18" x 22".
- Plan on 18" x 20" of usable fabric per fat quarter: half of the 40" usable width used for yardage.
- Pieces per fat quarter = (18 ÷ cut size, rounded down) × (20 ÷ cut size, rounded down).
- Fat quarters needed = pieces ÷ pieces per fat quarter, rounded up to a whole fat quarter.
- Borders, binding and long sashing strips are longer than 20" and need yardage, not fat quarters.
What a fat quarter is
A fat quarter is a quarter of a yard cut a different way. Sew4Home explains it from a one-yard cut of 44"-wide quilting cotton, which is 36" x 44": divide that piece into four equal parts and each one is 18" x 22". A regular quarter yard from the same bolt is a 9" x 44" strip. Both have the same area, 396 square inches, but the fat quarter's squarer shape lets you cut larger pieces from it.
Four fat quarters come from one yard, so 1 yard equals 4 fat quarters by area. That simple swap only holds when every piece fits inside one fat quarter, which the last sections cover.
The usable size: plan on 18" x 20"
The 22" side includes a selvage, and quilting cotton shrinks a little when washed and is trimmed square before cutting. For yardage, the fabric guide on this site plans with 40" of usable width, the same planning figure Missouri Star Quilt Co. uses for 42" cotton. Half of that is 20", so this guide plans each fat quarter as 18" x 20".
Pieces are cut at their finished size plus 1/2", because a 1/4" seam allowance is taken from each side. The Quilt Show notes that the right seam is whichever one gives the planned finished size, so test yours on scraps first.
- Fat quarter as sold: 18" x 22".
- Planning size: 18" x 20".
- Cut size of a square: finished size + 1/2".
Squares per fat quarter chart
Each figure is the number of squares across the 18" side (rounded down) times the number across the 20" side (rounded down). A partial square is waste, so it is never counted.
| Finished square | Cut size | Layout | Squares per fat quarter |
|---|---|---|---|
| 2" (5.1 cm) | 2 1/2" | 7 x 8 | 56 |
| 2 1/2" (6.4 cm) | 3" | 6 x 6 | 36 |
| 3" (7.6 cm) | 3 1/2" | 5 x 5 | 25 |
| 4" (10.2 cm) | 4 1/2" | 4 x 4 | 16 |
| 4 1/2" (11.4 cm) | 5" | 3 x 4 | 12 |
| 5" (12.7 cm) | 5 1/2" | 3 x 3 | 9 |
| 6" (15.2 cm) | 6 1/2" | 2 x 3 | 6 |
| 8" (20.3 cm) | 8 1/2" | 2 x 2 | 4 |
| 10" (25.4 cm) | 10 1/2" | 1 x 1 | 1 |
| 12" (30.5 cm) | 12 1/2" | 1 x 1 | 1 |
Worked example 1: a 50" x 60" throw with 5" squares
A 50" x 60" (127 x 152.4 cm) throw of 5" finished squares is 10 squares across and 12 down, so it needs 120 squares. Each square is cut at 5 1/2", and the chart shows 9 per fat quarter. 120 ÷ 9 = 13.33, rounded up to 14 fat quarters.
Compare that with yardage. The fabric guide on this site works the same top out at 2 3/4 yards of one fabric, which is 11 fat quarters by area. The fat quarter plan needs 3 more because a 5 1/2" square leaves a 1 1/2" strip on the 18" side and a 3 1/2" strip on the 20" side of every fat quarter. Some sizes fit a fat quarter well and some do not, so always count pieces instead of converting yards to fat quarters.
Worked example 2: a 48" x 60" throw with 4" squares
A 48" x 60" (121.9 x 152.4 cm) throw of 4" finished squares is 12 across and 15 down, or 180 squares. Cut at 4 1/2", a fat quarter gives 4 x 4 = 16 squares with almost no waste. 180 ÷ 16 = 11.25, rounded up to 12 fat quarters.
For a scrappy quilt with an even share of each print, divide first and round each print up on its own. With 12 different prints, each print supplies 15 squares, and 15 fits inside one fat quarter of 16, so 12 fat quarters still cover it. With 20 prints, each supplies 9 squares, so you need 20 fat quarters even though fewer would cover the total.
When fat quarters will not work
A fat quarter can only give pieces up to 18" x 20". Borders, binding strips, long sashing and wide setting pieces are usually longer than that and come from yardage cut across the width of the fabric. The backing is a separate, much larger piece. Plan those from yardage with the binding and backing guide, and use fat quarters for the blocks.
Strips are the exception that still works: a fat quarter gives 2 1/2"-wide strips about 20" long. Pieced binding or sashing from those short strips needs more seams, so count the joins before choosing that route.
What to check before you cut
Measure a fat quarter from the bundle after washing and trimming, because shops cut them from bolts of different widths and the usable size can be smaller than 18" x 20". If yours is smaller, recount the pieces with your own measurements. Check directional prints, which may only allow one orientation. Then cut one fat quarter and count the pieces before cutting the rest. The quilt pattern generator on this site counts pieces for every fabric in a layout, so you can compare its totals with your own fat quarter count.
Common questions
- How many fat quarters are in a yard?
- Four. A one-yard cut of 44"-wide cotton is 36" x 44", and dividing it into four equal parts gives four 18" x 22" fat quarters.
- How many 5" squares can I cut from a fat quarter?
- Twelve, if the usable fabric is at least 18" x 20": 3 squares across the 18" side and 4 across the 20" side. Squares cut at 5" finish at 4 1/2" with a 1/4" seam allowance.
- Is a fat quarter the same as a quarter yard?
- They have the same area, 396 square inches, but not the same shape. A quarter yard is a 9" x 44" strip; a fat quarter is 18" x 22", so it gives larger pieces.
- Can I convert a yardage pattern to fat quarters by multiplying by four?
- Only as a rough first check. Count the pieces each fat quarter really gives, because the leftovers differ by piece size, and plan borders, binding and backing from yardage.
About this page
Written and reviewed by Claire, Editor, Needle Nook. Last reviewed . General craft guidance; check your own gauge and measurements before cutting or stitching.
Facts on this page follow these references:
- Fat Quarter (glossary) ↗Sew4Home
- How to Calculate Quilt Backing Yardage ↗Missouri Star Quilt Co.
- What is a Seam Allowance? ↗The Quilt Show