Fat Quarter Calculator
A fat quarter is a yard quartered — 18 × 22 in, about 50 × 55 cm. Cutting 4.5 in (11.4 cm) squares gives four across and four down, so 16 squares with 671 cm² left over. When the piece is not square, turning it can yield more, so both orientations are counted and the better one shown.
Your numbers
Pieces you get
16
Per row
4
Fabric left over
671cm²
Formula
Pieces you get = ⌊Fat quarter width ÷ Piece width⌋ × ⌊Fat quarter length ÷ Piece length⌋
Enter the cut size, not the finished size; entering finished sizes leaves out the seam allowance and overstates the yield. Fat quarters are often cut off-square at the shop, so treat about 1 cm of one edge as unusable — if the layout only just fits, buy a second one.
What to enter
| Input | Default | Accepted range |
|---|---|---|
| Fat quarter width (cm)The short side of a fat quarter — the 18 in edge of a quartered yard. | 50 | 1 and up |
| Fat quarter length (cm)The long side, the 22 in half-width edge. | 55 | 1 and up |
| Piece width (cm)One piece across, as cut — seam allowance included. | 11.4 | 0.5 and up |
| Piece length (cm)One piece along, as cut — seam allowance included. | 11.4 | 0.5 and up |
Step by step
Quick reference table
Results when only Fat quarter width (cm) changes and everything else stays put.
| Fat quarter width (cm) | Pieces you get | Per row | Fabric left over (cm²) |
|---|---|---|---|
| 25 | 8 | 2 | 335 |
| 37.5 | 12 | 3 | 503 |
| 50 | 16 | 4 | 671 |
| 75 | 24 | 6 | 1,006 |
| 100 | 32 | 8 | 1,341 |
What each result means
| Result | At default values |
|---|---|
| Pieces you getHow many pieces that fabric yields. | 16 |
| Per rowPieces that sit side by side across the width. | 4 |
| Fabric left over (cm²)Area left after cutting, and it comes out as narrow offcuts. | 671 |
Common mistakes
Enter the cut size, not the finished size; entering finished sizes leaves out the seam allowance and overstates the yield. Fat quarters are often cut off-square at the shop, so treat about 1 cm of one edge as unusable — if the layout only just fits, buy a second one.
Glossary
- Fat quarter width
- The short side of a fat quarter — the 18 in edge of a quartered yard.
- Fat quarter length
- The long side, the 22 in half-width edge.
- Piece width
- One piece across, as cut — seam allowance included.
- Piece length
- One piece along, as cut — seam allowance included.
- Pieces you get
- How many pieces that fabric yields.
- Per row
- Pieces that sit side by side across the width.
- Fabric left over
- Area left after cutting, and it comes out as narrow offcuts.
Frequently asked questions
Q. How is Fat Quarter Calculator calculated?
Pieces you get = ⌊Fat quarter width ÷ Piece width⌋ × ⌊Fat quarter length ÷ Piece length⌋ — A fat quarter is a yard quartered — 18 × 22 in, about 50 × 55 cm. Cutting 4.5 in (11.4 cm) squares gives four across and four down, so 16 squares with 671 cm² left over. When the piece is not square, turning it can yield more, so both orientations are counted and the better one shown.
Q. Can you walk through an example?
With Fat quarter width 50cm, Fat quarter length 55cm, Piece width 11.4cm, Piece length 11.4cm, the answer is Pieces you get 16.
Q. What do I need to enter?
Enter Fat quarter width, Fat quarter length, Piece width, Piece length. The result recalculates as you type, and an empty box counts as zero.
Q. How much does the answer move if I change a number?
Changing only Fat quarter width (cm) moves the answer to Fat quarter width (cm) 25 → Pieces you get 8 and Fat quarter width (cm) 100 → Pieces you get 32. The table below lays out five steps.
Q. How are the numbers rounded?
Money is shown to the nearest whole unit, percentages to one decimal place and everything else to two. What you see is rounded; the calculation itself carries the unrounded value forward.
Q. Anything to watch out for?
Enter the cut size, not the finished size; entering finished sizes leaves out the seam allowance and overstates the yield. Fat quarters are often cut off-square at the shop, so treat about 1 cm of one edge as unusable — if the layout only just fits, buy a second one.
Related calculators
Materials differ in density and absorption. If your label states a figure, use it — the defaults here are only common values.