Quilt Math
12-02-2010, 07:06 PM
#1
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Join Date: Nov 2010
Location: Austin, TX
Posts: 70
I had read that quilt math was easy and I would like to know where I could learn how to do the quilt math. I love to make quits with no patterns, but always buy too much fabric or not enough. Any help I can get I would so appreciate it.
12-02-2010, 11:35 PM
#5
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Join Date: Mar 2010
Location: Sturbridge, Ma
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Quilt math is basically:
Looking at your block.
Measuring each piece
Determining square inches of that piece
Multiplying the number of times that piece will be used
Then convert to yardage.
Yardage is calculated at 42"x36" With 42" being the average width of fabric.
Looking at your block.
Measuring each piece
Determining square inches of that piece
Multiplying the number of times that piece will be used
Then convert to yardage.
Yardage is calculated at 42"x36" With 42" being the average width of fabric.
12-02-2010, 11:48 PM
#6
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Join Date: Mar 2010
Location: Sturbridge, Ma
Posts: 3,992
To continue with math
Say you want to do a 12" 9 patch for a queen quilt.
Quilt is 96"x108" There will be a total of 72 blocks in the quilt. 96" divided by 12" and 108" divided by 12 = 72
Each 9 patch block contains 9 squares finished at 4". So cut will be 4.5"
4.5"x4.5" = 20.25 square inches.
20.25 x 9 = 182.25 square inches each block
182.25 x 72 blocks is 13122 total square inches.
1512 square inches in a yd of fabric
13122 divided by 1512 = 8.67 total yds.
Now, assume you want to use two colors in your blocks then the 8.67 divided by 2 is 4.33 or little over 4 and 1/3 yd of each color. But add a half yard for miscuts.
Calculating for binding.
Measure around quilt = 408" width of fabric is 42"
Divide 42 into 408 = 9.7 strips (make it 10 strips)
If each strip is cut 2.5" then 2.5 x 10 is 25 inches of fabric for the binding.
I woke up and couldn't sleep
Say you want to do a 12" 9 patch for a queen quilt.
Quilt is 96"x108" There will be a total of 72 blocks in the quilt. 96" divided by 12" and 108" divided by 12 = 72
Each 9 patch block contains 9 squares finished at 4". So cut will be 4.5"
4.5"x4.5" = 20.25 square inches.
20.25 x 9 = 182.25 square inches each block
182.25 x 72 blocks is 13122 total square inches.
1512 square inches in a yd of fabric
13122 divided by 1512 = 8.67 total yds.
Now, assume you want to use two colors in your blocks then the 8.67 divided by 2 is 4.33 or little over 4 and 1/3 yd of each color. But add a half yard for miscuts.
Calculating for binding.
Measure around quilt = 408" width of fabric is 42"
Divide 42 into 408 = 9.7 strips (make it 10 strips)
If each strip is cut 2.5" then 2.5 x 10 is 25 inches of fabric for the binding.
I woke up and couldn't sleep
12-03-2010, 01:56 AM
#7
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Join Date: Jan 2009
Posts: 4,688
If you want some guidance on quilter's math, Quilt University has a class that covers all of it. It's one of their most popular classes. The next class starts April 15th and it's three classes, plus a bonus lesson all for only $27. http://www.quiltuniversity.com/catalog.htm
12-03-2010, 04:18 AM
#9
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Join Date: Jun 2010
Location: Pflugerville, TX
Posts: 230
Sorry you couldn't sleep - but we've all benefitted! My alegbra I teacher - bless her heart - would be laughing her head off right now if she knew I was quiling! She once told me to never, ever, attempt anything other than business math! :lol:
12-03-2010, 06:23 AM
#10
Super Member
Join Date: Jul 2010
Posts: 1,029
One thing I do is I only use 40 as my width because I am finding too many pieces of quality fabric (LQS not chain stores) that after washing are less than 42. So I have learned to give myself a little bit of wiggle room. I might end up with some scraps, but I would rather do that than not have enough!
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