Fat Quarter & Precut Cutting Planner
A fat quarter and a long quarter are the same area, and which cuts more genuinely flips with the size — fat wins 9 of 16, long wins 3.
Same fabric, different shape, and the winner flips
Both are a quarter yard. A long quarter is the plain cut — 9″ off the bolt, so 9×44″. A fat quarter is a half-yard cut in half the other way: 18×22″. Identical area, 396 square inches each. What almost nobody quantifies is how differently they cut.
| Cut size | Fat quarter | Long quarter | Better |
|---|---|---|---|
| 2″ | 99 | 88 | fat quarter (1.13×) |
| 2.5″ | 56 | 51 | fat quarter (1.10×) |
| 3″ | 42 | 42 | level |
| 3.5″ | 30 | 24 | fat quarter (1.25×) |
| 4″ | 20 | 22 | long quarter (1.10×) |
| 4.5″ | 16 | 18 | long quarter (1.13×) |
| 5″ | 12 | 8 | fat quarter (1.50×) |
| 5.5″ | 12 | 8 | fat quarter (1.50×) |
| 6″ | 9 | 7 | fat quarter (1.29×) |
| 8″ | 4 | 5 | long quarter (1.25×) |
| 9″ | 4 | 4 | level |
| 10″ | 2 | 0 | fat quarter |
Over these sizes the fat quarter wins 7 and the long quarter wins 3. So "fat quarters are just better" is wrong a good part of the time — at 5 inches the fat quarter gives half as many again, and at 4 inches the long quarter quietly wins.
The limit no area calculation can see
A long quarter cannot cut anything wider than 9 inches, however much area it has. Nine inches is simply how wide it is. That is the real reason fat quarters exist, and it is a shape constraint rather than a quantity one — which is why yardage arithmetic will never warn you about it. If your pattern has a 18-inch piece in it, no amount of long quarters will do.
Trimming a precut costs the square of what it looks like
You judge a trim along an edge and you pay for it by area, so it always costs more than it feels like. The loss is 1 − (new ÷ old)², which for small trims is roughly twice the edge figure.
| Trim | Off each side | Of the fabric |
|---|---|---|
| 5″ → 4.5″ | 10% | 19% |
| 5″ → 4″ | 20% | 36% |
| 10″ → 9.5″ | 5% | 10% |
| 10″ → 9″ | 10% | 19% |
| 2.5″ → 2″ | 20% | 36% |
Trimming a charm square by half an inch throws away nearly a fifth of it. Which is the argument for buying the precut your pattern actually wants rather than the pretty one and cutting it down — and for checking, before you buy, that the numbers line up.
What is in a bundle
| Precut | Size | Usual count | |
|---|---|---|---|
| Mini charm pack | 2.5″ square | 42 | Squares. |
| Charm pack | 5″ square | 42 | Squares. |
| Layer cake | 10″ square | 42 | Squares. |
| Jelly roll | 2.5″ × 42″ strip | 40 | Strips the full width of the fabric. |
| Honey bun | 1.5″ × 42″ strip | 40 | Narrow strips. |
| Dessert roll | 5″ × 42″ strip | 20 | Wide strips. |
Counts vary between manufacturers. Forty-two is the usual figure for a charm pack but it is a convention, not a standard, so check the band before you plan a quilt down to the last square.
Notes
- These are nominal sizes. A "fat quarter" is cut by a human with scissors from fabric that may have shrunk, so measure yours. The difference is usually under half an inch and occasionally it is the half inch that matters.
- Rotating the cut is free. This tries both orientations and takes the better, which sometimes changes the answer — a 3×9 cut and a 9×3 cut are the same piece but not always the same yield.
- Precut edges are often pinked. The zigzag edge means the true measurement is taken from the middle of the points, so a 5″ charm can measure 4⅞″ at the valleys. Cut from the outer points.
- Leave a margin. The yields here assume perfect cutting from a perfectly square piece. Neither is true, so if the answer is exactly enough, buy one more.
How to use
- Pick the piece of fabric you actually have.
- Enter the cut size — same width and height for squares.
- Read the yield, and how many pieces you need for your total.
- Check the fat-versus-long comparison before buying.
Frequently asked questions
How many 5-inch squares can I get from a fat quarter?
Twelve, laid out three across by four down in an 18 by 22 inch piece. A long quarter of exactly the same area gives only eight, because 9 inches of width takes just one 5-inch square with 4 inches wasted.
What is the difference between a fat quarter and a long quarter?
The shape, not the amount. Both are a quarter yard — 396 square inches. A long quarter is 9 by 44 inches, cut straight off the bolt; a fat quarter is 18 by 22, a half-yard cut in half the other way. Identical fabric, very different cutting.
Is a fat quarter always better?
No, and this surprises people. Across sixteen common cut sizes the fat quarter wins nine, the long quarter wins three, and four are level. At 4 and 4.5 inches the long quarter quietly comes out ahead, because 44 inches of length divides more kindly than 22 does.
Why can a long quarter not cut large pieces?
Because it is only 9 inches wide, and no amount of area changes that. Anything wider than 9 inches is simply impossible from a long quarter however much of it you have. That is a shape constraint rather than a quantity one, which is exactly why yardage arithmetic never warns you about it — and it is the real reason fat quarters exist.
How much fabric do I lose trimming a charm square?
More than it looks. Trimming a 5-inch charm to 4.5 is ten per cent off each side but nineteen per cent of the fabric, because area goes as the square. Down to 4 inches is twenty per cent a side and thirty-six per cent of the area. You judge the trim along an edge and pay for it by area.
How many squares does a jelly roll strip give?
Sixteen 2.5-inch squares from a 42-inch strip. The exact figure depends on your fabric's usable width, which is often a little under 42 once selvedges are gone — so check before planning down to the last square.
How many pieces are in a charm pack?
Usually 42, but it is a convention rather than a standard and manufacturers differ. Check the band, especially if a pattern needs every square, because being one short of a precut means buying a whole second pack.
Are precut sizes exact?
Close, but they are cut by machine from fabric that may have shrunk, and the edges are often pinked. The zigzag means the true measurement runs from the outer points, so a 5-inch charm can measure 4⅞ at the valleys. Cut from the points and leave yourself a margin.
Does this send anything anywhere?
No. Everything is calculated in your browser and nothing is stored or uploaded.
🔒 This tool runs entirely in your browser. Nothing you enter is uploaded, logged, or stored.