Open Nine patch in the studio. The form on this page is that calculator.
Why nine-patch squares are often an awkward size
A nine patch is nine equal squares. The cut size is the unfinished block divided by three, and the unfinished block is the finished size plus half an inch. A 6 inch finished nine patch wants squares of 2 1/6 inches, which is not a mark on most rulers. A 9 inch block wants 3 1/6. You can cut those exactly, or you can choose a finished size that lands on a clean number and let the quilt grow from that.
The yardage assumes the usual coloring: five squares of a darker fabric and four of a lighter one, like a checkerboard with the dark in the corners and the center. Swap the names if your pattern does the opposite. The nine patch block guide covers the seam order.
How the nine-patch square is calculated
- Unfinished block = finished size + 1/2 inch
- Each square = unfinished block รท 3
- Dark squares = 5 per block. Light squares = 4 per block.
A size that divides cleanly is the one most people cut. A block that finishes at 5 1/2, 8 1/2, or 11 1/2 inches uses 2, 3, or 4 inch squares. The chart keeps the awkward sizes too, because patterns ask for them by name.
Nine-patch square sizes
The clean rows are the ones that land on a whole inch. The others are a sixth or a third, and the calculator prints them that way rather than rounding to a ruler mark the seam does not land on.
| Finished block | Square to cut | On a ruler? |
|---|---|---|
| 5 1/2 in | 2 in | Yes |
| 6 in | 2 1/6 in | Awkward |
| 6 1/2 in | 2 1/3 in | Awkward |
| 8 1/2 in | 3 in | Yes |
| 9 in | 3 1/6 in | Awkward |
| 11 1/2 in | 4 in | Yes |
| 12 in | 4 1/6 in | Awkward |
How to use this calculator
- Enter the finished block from the pattern. If you are designing, consider a size from the clean rows of the chart.
- Enter how many blocks, and the usable fabric width. The card splits the squares five-and-four and turns each pile into yardage.
- Cut both fabrics at the square size. Sew in three rows of three, then sew the rows together.
Tips for nine patches
- Pick the square first when you can. A 2 1/2 inch square, finished into a block of 6 inches after seams, is a different block from a 6 inch finished nine patch. Read which number the pattern means.
- Precut squares skip this cut. A charm is already 5 inches. The precut calculator is the one that asks how many charms you need.
- Press the seams of each row in opposite directions so the intersections nest.
When the piece is part of a whole quilt. A nine-patch quilt is this block repeated. Sashing and borders are separate cuts, added after you know the grid. The fabric calculator counts every piece in a design, then adds binding, backing, and batting. These pages answer one question at a time.