I am working on a twin scrappy quilt. This is the first quilt that I am working on that didn't come from a set pattern. I'm just making it up as I go. I could use some help on the math to make sure I end up with a twin quilt. Some how all of my twin quilts end up way too small (I just tell every body that it is a lap quilt. I'm the only one who knows that it didn't turn out right).

Ok... here we go.... (finished, unfinished translates into seam allowance)

Twin batting size – 72 x 90

Blocks, unfinished – 7 in
Blocks, finished – 6.5 in
Sash, unfinished – 2.5 in
Sash, finished – 2 in

Boarder, white, finished – 2 in
Boarder, scrappy, finished – 2 in
Boarder, white, finished – 2 in
Total boarder – 6 in on each side

7 blocks + 6 sash = 57.5
9 blocks + 8 sash = 74.5

Finished quilt size – 69 x 86

Total blocks needed = 63

What to you think? Where the math quilt gods kind to me, or do I need to rethink some things?

finished size, including binding: 70" x 87"

the finished border is 6", but remember that the binding is approximately another 1/4" on each side, not counting your "finished" measurements. So you need to add 1/2" to each measurement to get the final size.

I was lost when you said Math- I just let things happen but I am sure there are people on this board who will help. Good Luck!

The only thing you didn't consider is the quilting. Depending on how heavy the quilting is, your quilt will shrink some.

That depends on how you do your binding. Mine don't add to the dimensions.

From my figures 69 1/2" X 86 1/2" your close enough in your figures. The one thing I would mention is maybe getting a larger size batting to allow for quilting ease.
Good luck and show us pictures!

Thanks! I'd forgotten about allowing for quilting ease and thanks for the heads up about the binding. Hmmmm.....

I might make my boarders a bit wider to give some breathing room. I think I will piece the rest of the top and put it on the bed to see how much of a boarder I need. I like the idea of using a larger batting. I was thinking of a larger drop on this quilt. The larger batting would keep my options open.

Now that I have a handle on the math I need to practice my 1/4 in seams.... I keep reminding myself, progress not perfection.
thanks for all the help!

Out of curiosity, how do you do your binding? Say I want my final border to be 6". I cut it 6 1/2" - 1/4" gets in the seam allowance with the quilt center and 1/4" gets in the binding, leaving 6" for the border. So my quilt is the center + 12" (6" for each border) + 1/2" (1/4" for each binding side).

I understand you now. I thought you were saying that your binding adds significantly to the overall dimensions of the quilt. Some people do it that way. I actually add 1/2 to 3/8 for my binding dimension, because I usually do it by machine.