A fat quarter is a quarter yard cut wide: 18 × 21 usable inches that cut far better than the skinny strip. Enter your piece size; you get the count one fat quarter yields, the cutting layout that wins, and how many to buy for your pattern.
Your Pieces
Fine-tune: usable fat quarter size
One Fat Quarter Yields
12pieces
5 × 5″ pieces from 18 × 21″ usable · layout 3 × 4
- Pieces per fat quarter12 (3 × 4)
- Fat quarters for 56 pieces5 (4 spare)
- Same pieces by the yard1 yd (7 strips)
The Formula
pieces = ⌊18 ÷ height⌋ × ⌊21 ÷ width⌋ · tried both ways, the better layout winsA fat quarter is a half-yard cut in half the other way: 18 in deep by half the fabric’s width. The same quarter yard of cloth as the long skinny quarter, in a shape that fits real patches.
Worked Example
Charm squares (5 in cut) from an 18 × 21 fat quarter:
- Rows: ⌊18 ÷ 5⌋ = 3. Columns: ⌊21 ÷ 5⌋ = 4. One fat quarter yields 12 charm squares, with a 3 × 21 strip and three 1 × 5 slivers left for scraps.
- A pattern asking for 56 charms: 56 ÷ 12 → 5 fat quarters, with 4 squares to spare.
Pieces per Fat Quarter
| Cut size | Per fat quarter | Layout |
|---|---|---|
| 2½″ square | 56 | 7 × 8 |
| 3″ square | 42 | 6 × 7 |
| 3½″ square | 30 | 5 × 6 |
| 4″ square | 20 | 4 × 5 |
| 4½″ square | 16 | 4 × 4 |
| 5″ square | 12 | 3 × 4 |
| 6½″ square | 6 | 2 × 3 |
| 2½ × 21″ strip | 7 | stacked |
| 10″ square | 2 | 1 × 2 |
How to Measure Your Inputs
- Use cut sizes, finished size plus ½ in for patches sewn with ¼ in seams. A 4½ in finished square cuts at 5.
- Measure your actual fat quarter. Shops cut from 42–44 in bolts, so the half-width runs 21–22 in; pressing and squaring-up usually leave 21 usable. The fine-tune field takes whatever yours tapes.
- Directional prints lock the piece’s rotation: enter width and height as the print demands and skip the flipped layout the calculator would otherwise try.
Assumptions and Defaults
- Usable size defaults to 18 × 21 in, the trimmed reality of a nominal 18 × 22 cut.
- Pieces are cut on grain in straight rows; the calculator does not stagger or rotate single pieces to squeeze one more from the gaps.
- Buying count rounds up whole fat quarters; leftovers stay in your scrap bin’s favor.
Fat Quarter Questions, Answered
What size is a fat quarter?
A fat quarter is nominally 18 × 22 in, a half yard of quilting cotton cut in half along the fold. Because bolts vary from 42 to 44 in wide and shops trim the edges, plan on 18 × 21 in usable, the same amount of cloth as a 9 × 42 in quarter-yard strip in a far more useful shape.
How many fat quarters make a quilt?
By area, a 50 × 65 in throw holds about 12 fat quarters of top fabric if every inch were pieced in. Real patterns lose some to trimming and call for variety, so most fat quarter throw patterns ask for 10 to 16, and entering your pattern’s piece count above gives the exact number.
Is a fat quarter the same as a quarter yard?
A fat quarter holds the same amount of fabric as a quarter yard, but in a different shape. A quarter yard off the bolt is 9 × 42 in, fine for strips and binding but cramped for anything over 8 in, whereas a fat quarter’s 18 × 21 in cuts a 10 in square that the narrow strip never can.
How many 5 inch squares can I cut from a fat quarter?
You can cut twelve 5 in squares from a fat quarter, arranged in a 3 × 4 grid. The chart above lists the other common cut sizes, and the calculator handles rectangles and unusual sizes as well, so you can plan any patch your pattern calls for.