Quilt Block Count Calculator
Enter your target quilt size, the finished block size and an optional border. The calculator tells you how many blocks fit across and down, and how many blocks you need in total.
Tip: use URL parameters to pre-fill, e.g. ?quiltWidth=90&quiltLength=102&blockSize=12&borderWidth=6.
How the count works
Subtract the border widths from the target size to get the block field, then divide by the finished block size and round down. A 90 x 102-inch quilt with a 6-inch border leaves a 78 x 90-inch field, which fits 6 blocks across and 7 blocks down at 12 inches — 42 blocks total.
Blocks rarely fill the field exactly. The leftover inches are trimmed evenly from the outside blocks, or absorbed by a slightly wider border. This calculator shows the whole-block grid, which is what you plan and cut for.
What each input means
Target quilt size: the finished size before quilting and trimming, from your pattern or a standard size chart.
Finished block size: the block size after seams, not the cut size. The quilt block calculator converts it to a cut size.
Border width: the finished width of a single border around the blocks. Enter 0 if your quilt has no border.
Common questions
What if my number of blocks is odd?
Odd grids are fine — they just change the layout. For example, 5 x 6 blocks makes a rectangular grid that works well for lap and twin quilts.
Do sashing strips change the count?
Yes. Sashing adds width and length between blocks, so you need fewer blocks to reach the same quilt size. The sashing calculator handles that layout.
How much should I trim from the edges?
Trim each side by half the leftover after quilting, keeping the quilt centered. A little extra is fine — the binding will cover up to about half an inch of edge per side.