Open Snowball in the studio. The form on this page is that calculator.
Why the corner size is the whole design
A snowball is a square with its corners replaced by small triangles. You sew a small square to each corner, flip it open, and trim the dog-ear. What you see of the triangle along the edge of the block is the finished corner. A modest corner leaves a big square of the center fabric. A corner that reaches halfway across the block is no longer a snowball: the seams meet, and you have made a square in a square.
The calculator refuses a corner that would overlap. Half the block is as large as a corner can be. At that size, use the square in a square calculator.
How snowball squares are calculated
- Center = finished block + 1/2 inch
- Corner square = finished corner + 1/2 inch
- Corners = four per block
An 8 inch block with 2 inch corners is a center of 8 1/2 inches and corner squares of 2 1/2 inches. Twelve of those blocks are 12 centers and 48 corner squares.
Snowball cutting chart
The corner is the finished size you see along the edge, before seam allowance.
| Finished block | Finished corner | Center cut | Corner cut |
|---|---|---|---|
| 6 in | 1 1/2 in | 6 1/2 in | 2 in |
| 8 in | 2 in | 8 1/2 in | 2 1/2 in |
| 10 in | 2 1/2 in | 10 1/2 in | 3 in |
| 12 in | 3 in | 12 1/2 in | 3 1/2 in |
How to use this calculator
- Enter the finished block and the finished corner. Keep the corner at half the block or smaller.
- Enter the number of blocks. The card multiplies centers by the count and corners by four times the count.
- Draw the diagonal on the back of each corner square, sew, flip, and trim the dog-ear even with the center.
Tips for snowball blocks
- Chain-piece the corners. All four corners of a block are the same square, and a quilt's worth of them is a long chain.
- Directional center fabric stays upright, because you are not rotating the center. The corner fabric is the one that gets flipped.
- Sashing changes the look more than the cut. The same snowball with and without sashing is a different quilt. The sashing calculator sizes the strips between blocks.
When the piece is part of a whole quilt. A snowball quilt is this block on a grid. Draw it once and the yardage follows the count. The fabric calculator counts every piece in a design, then adds binding, backing, and batting. These pages answer one question at a time.