Welcome to the Quilting Board!

Already a member? Login above
loginabove
OR
To post questions, help other quilters and reduce advertising (like the one on your left), join our quilting community. It's free!

Results 1 to 16 of 16

Thread: Fabric Question for a math whiz

  1. #1
    Junior Member
    Join Date
    Oct 2012
    Location
    at the foot of the Ouichita Mountains, SE Oklahoma
    Posts
    272

    Fabric Question for a math whiz

    I have a quilt pattern that doesn't give rotary cutting instructions. It just says how many squares and strips to cut. EX: 70 strips @ 2 x 3 1/2, 70 strip @ 2 x 5 1/2, 28 strip @ 2x12, etc.

    I know they can be rotary cut, but for the life of me I can't figure out how to calculate how many strips I'd need to cut.

    Hoping someone will help me out. Soooooo....

    If a quilt patterns says to cut 28 2x12-inch strips and my material is 44 inches wide...how many strips do I cut?

    What is the formula for calculating that.

    Sorry to be such a dummy. I have a Master's degree but it wasn't in math. LOL

    Stuck here.

    TIA,
    Dray

  2. #2
    Power Poster Prism99's Avatar
    Join Date
    Dec 2008
    Location
    Western Wisconsin
    Posts
    12,152
    Blog Entries
    1
    Quote Originally Posted by dray965 View Post
    If a quilt patterns says to cut 28 2x12-inch strips and my material is 44 inches wide...how many strips do I cut?

    What is the formula for calculating that.
    Usually we cut fabric WOF (width-of-fabric), which is from one selvedge to the other (your WOF is 44 inches). So, you would be cutting 2-inch strips WOF. If the fabric is 44 inches wide, you can get only three 12-inch strips from the width-of-fabric. The rest is scrap. This calculation would be:
    X*12 = 48
    X= 48/12
    X=3

    You need 28 2x12-inch strips and you can get 3 per WOF. 28/3 = 9.33 so you would need 10 strips WOF to get 28 2x12-inch strips. (You would need only one 2x12-inch strip from that last WOF.)

    Gosh, I didn't realize it would look so confusing when I started this! Hope it helps some.

  3. #3
    Super Member Peckish's Avatar
    Join Date
    May 2011
    Location
    Pacific NW
    Posts
    6,318
    Blog Entries
    1
    Quote Originally Posted by dray965 View Post
    If a quilt patterns says to cut 28 2x12-inch strips and my material is 44 inches wide...how many strips do I cut?

    What is the formula for calculating that.
    It's simple division. 44 divided by 12, or 44 divided by 2, whichever fits best. 12 does not go evenly into 44, you will have quite a chunk of fabric left over. 44 divided by 2 is 22, you can cut 22 strips that are 12 inches long. Then you will need to cut 6 more strips to equal 28.

    Hope this helps.

    eta: whoops Prism beat me to it, although she took a different route, lol.
    Last edited by Peckish; 03-02-2013 at 08:06 AM.

  4. #4
    Junior Member
    Join Date
    Oct 2012
    Location
    at the foot of the Ouichita Mountains, SE Oklahoma
    Posts
    272
    Thanks This had my head spinning.

    Dray

  5. #5
    Power Poster ckcowl's Avatar
    Join Date
    Feb 2009
    Location
    Northern Michigan
    Posts
    11,302
    Blog Entries
    1
    if you cut your widest measurement first---such as 12" wide strip---then from that cut your smaller measurement (like 2") you will find it easier to figure out-
    remember you need to remove salvages so, you will not have 44" of usable fabric.

    so- 70 pieces that are 2" X 3 1/2" you would start with cutting 3 1/2" strips- you can then cut (20- 21) 2" cuts from each strip- you need 70...so 3 strips gives you 60-63, cut a 4th strip in half if you want for 7-10 more pieces.

    70 @ 5 1/2" you do the same way- cut your strips 5 1/2" wide (if you start with the widest needed then you can use 1/2 of the 4th strip for your extra (10) 5 1/2" pieces and the other half of it for the 3 1/2" pieces

    and the 28 12" x 2" you would cut 2 strips 12"...(20) 2" pieces from one---you only need 8 from the second strip---again you could use the other half of the strip to cut some of the smaller pieces if you start with the widest strips needed & work your way down....good way to (stretch) your fabric. always start with the largest pieces you need & work your way down
    hiding away in my stash where i'm warm, safe and happy

  6. #6
    Senior Member rush88888's Avatar
    Join Date
    May 2012
    Location
    leland nc
    Posts
    440
    [QUOTE=Prism99;5898546]Usually we cut fabric WOF (width-of-fabric), which is from one selvedge to the other (your WOF is 44 inches). So, you would be cutting 2-inch strips WOF. If the fabric is 44 inches wide, you can get only three 12-inch strips from the width-of-fabric. The rest is scrap. This calculation would be:
    X*12 = 48
    X= 48/12
    X=3

    You need 28 2x12-inch strips and you can get 3 per WOF. 28/3 = 9.33 so you would need 10 strips WOF to get 28 2x12-inch strips. (You would need only one 2x12-inch strip from that last WOF.)
    QUOTE]

    actually, using this formula, x = 4 (48 divided by 12 is 4)
    "perfection is the enemy of done."
    "the secret to having it all is knowing you already do."

  7. #7
    Power Poster Prism99's Avatar
    Join Date
    Dec 2008
    Location
    Western Wisconsin
    Posts
    12,152
    Blog Entries
    1
    [QUOTE=rush88888;5899128]
    Quote Originally Posted by Prism99 View Post
    Usually we cut fabric WOF (width-of-fabric), which is from one selvedge to the other (your WOF is 44 inches). So, you would be cutting 2-inch strips WOF. If the fabric is 44 inches wide, you can get only three 12-inch strips from the width-of-fabric. The rest is scrap. This calculation would be:
    X*12 = 48
    X= 48/12
    X=3

    You need 28 2x12-inch strips and you can get 3 per WOF. 28/3 = 9.33 so you would need 10 strips WOF to get 28 2x12-inch strips. (You would need only one 2x12-inch strip from that last WOF.)
    QUOTE]

    actually, using this formula, x = 4 (48 divided by 12 is 4)
    Yikes! It is supposed to be 44, not 48. And I should have mentioned to drop any remainder and use only the whole number.

  8. #8
    Super Member GrannieAnnie's Avatar
    Join Date
    Aug 2010
    Location
    S. W. Indiana
    Posts
    7,489
    Quote Originally Posted by dray965 View Post
    I have a quilt pattern that doesn't give rotary cutting instructions. It just says how many squares and strips to cut. EX: 70 strips @ 2 x 3 1/2, 70 strip @ 2 x 5 1/2, 28 strip @ 2x12, etc.

    I know they can be rotary cut, but for the life of me I can't figure out how to calculate how many strips I'd need to cut.

    Hoping someone will help me out. Soooooo....

    If a quilt patterns says to cut 28 2x12-inch strips and my material is 44 inches wide...how many strips do I cut?

    What is the formula for calculating that.

    Sorry to be such a dummy. I have a Master's degree but it wasn't in math. LOL

    Stuck here.

    TIA,
    Dray
    Get yourself a cup of coffee and a caluclator and look at this again. It's a whole lot easier than you are trying to make it.

    Use your calculator. Your fabric is about 42" of usable fabric (doesn't count the selvages) Divide 42 by the length of your NEEDED piece. So for the 12 inch pieces you'd get 3.5 strips that are 12 inches long. Use 3 and the half one which would be 6" lay aside for something else.

    IN 25 words or less, anything to the right of the decimal point will go into your scrap pile.

    I'm going to do Tula Pink's stacks. One of the required pieces needs to be 18.5" long. So I'd divide 42 by 18.5 (and without a calculator) I know I'll get two strips (total 37" which is less than the 42" WOF. With a calculator the exact number is 2.2702 strips.......................... Which would leave a scrap of about 5".

    If you are using standard sized fabric ie. 42-44" this method will work NO MATTER HOW WIDE THE PIECE IS, as long as you are cutting WOF. You'd calculate a 2" x 12" piece the same way you'd calculate a 6" x 12" piece or a 12" x 12" piece.

    Not to be bossy or anything--------cause I can be------but print this out and put in on the front page of your pattern folder.

    Now, wasn't that easy!
    Bad Spellers of the World
    U N T I E

  9. #9
    Super Member GrannieAnnie's Avatar
    Join Date
    Aug 2010
    Location
    S. W. Indiana
    Posts
    7,489
    [QUOTE=rush88888;5899128]
    Quote Originally Posted by Prism99 View Post
    Usually we cut fabric WOF (width-of-fabric), which is from one selvedge to the other (your WOF is 44 inches). So, you would be cutting 2-inch strips WOF. If the fabric is 44 inches wide, you can get only three 12-inch strips from the width-of-fabric. The rest is scrap. This calculation would be:
    X*12 = 48
    X= 48/12
    X=3

    You need 28 2x12-inch strips and you can get 3 per WOF. 28/3 = 9.33 so you would need 10 strips WOF to get 28 2x12-inch strips. (You would need only one 2x12-inch strip from that last WOF.)
    QUOTE]

    actually, using this formula, x = 4 (48 divided by 12 is 4)
    but our fabric is usually not 48" of usable cloth
    Bad Spellers of the World
    U N T I E

  10. #10
    Super Member Girlfriend's Avatar
    Join Date
    Sep 2012
    Location
    San Clemente, CA
    Posts
    1,171
    Quote Originally Posted by Prism99 View Post
    Usually we cut fabric WOF (width-of-fabric), which is from one selvedge to the other (your WOF is 44 inches). So, you would be cutting 2-inch strips WOF. If the fabric is 44 inches wide, you can get only three 12-inch strips from the width-of-fabric. The rest is scrap. This calculation would be:
    X*12 = 48
    X= 48/12
    X=3

    You need 28 2x12-inch strips and you can get 3 per WOF. 28/3 = 9.33 so you would need 10 strips WOF to get 28 2x12-inch strips. (You would need only one 2x12-inch strip from that last WOF.)

    Gosh, I didn't realize it would look so confusing when I started this! Hope it helps some.

    And so, if she were to go buy fabric with these kind of directions, how much fabric would she need to buy? 10 strips x 2" = 20" of fabric, how much yardage is that? (This is where I struggle the most). I figured the next cut up from 1/2 of a yard, which is 5/8 of a yard?

  11. #11
    Super Member Peckish's Avatar
    Join Date
    May 2011
    Location
    Pacific NW
    Posts
    6,318
    Blog Entries
    1
    36" = 1 yard
    27" = 3/4 yard
    18" = half yard
    9" = quarter yard

    I've NEVER been to any quilt shop or fabric store where you could not ask for inches instead of yardage. In other words, if you need 20 inches, they should be able to either cut 20 inches, or tell you the closest fraction, which in this case you are correct, it would be 5/8. In other words, don't be afraid to say "I need 20 inches, what's the closest to that you can cut?"

  12. #12
    Power Poster RedGarnet222's Avatar
    Join Date
    Jan 2009
    Location
    Reno, Nv
    Posts
    14,800
    I guess I am the odd man out because I would first cut the 12 inch width off the fabric and cut it down to the 2 inch widths. This is my reasoning. The long twelve inches need to be stable, so the length is the most stable side of the fabric. The fabric would give you 20 strips on the first strip after being cut down, You then cut the remaining strip only partially, so you have enough to make up the 8 remaining needed 2 inch strips. Which if it is doubled would be four inches. Then use the width of fabric for the other strips that aren't so long.
    Last edited by RedGarnet222; 03-02-2013 at 04:29 PM.
    RedGarnet222

    "Take your needle, my child, and work at your pattern ... It will come out a rose by and by. Life is like that ...one stitch at a time, taken patiently."
    *Oliver Wendell Holms

  13. #13
    Power Poster Prism99's Avatar
    Join Date
    Dec 2008
    Location
    Western Wisconsin
    Posts
    12,152
    Blog Entries
    1
    Girlfriend, you're right on track. Half a yard would be 18", which is not enough. I always buy more than I think I will need to allow for crooked cutting and my mistakes, so I would up the yardage to 3/4 of a yard (24"). Although 5/8 of a yard is adequate (22.5"), it doesn't allow for mistakes. I always go up a little more and add any scraps to my stash.

    If you have a calculator, an easy way to figure out how many inches is in 5/8 of a yard is to do this: 36 times 5 divided by 8. The result is the number of inches in 5/8 yard. This works for all fractions because a yard is always 36.

  14. #14
    Junior Member
    Join Date
    Oct 2012
    Location
    at the foot of the Ouichita Mountains, SE Oklahoma
    Posts
    272
    wow...lots of ways to do the same thing. I finally did the suggestion that said I should measure the 12-inch wide strip and cut the 2-inx12's from that.

    Thanks for all the ways of doing it...and yes, it is a good idea to print it all out and put it in a folder.

    Thanks to everyone,

    Dray

  15. #15
    Super Member GrannieAnnie's Avatar
    Join Date
    Aug 2010
    Location
    S. W. Indiana
    Posts
    7,489
    Quote Originally Posted by Prism99 View Post
    Girlfriend, you're right on track. Half a yard would be 18", which is not enough. I always buy more than I think I will need to allow for crooked cutting and my mistakes, so I would up the yardage to 3/4 of a yard (24"). Although 5/8 of a yard is adequate (22.5"), it doesn't allow for mistakes. I always go up a little more and add any scraps to my stash.

    If you have a calculator, an easy way to figure out how many inches is in 5/8 of a yard is to do this: 36 times 5 divided by 8. The result is the number of inches in 5/8 yard. This works for all fractions because a yard is always 36.

    I always allow at least a quarter of a yard for crooked cutting. And don't mind at all getting at least a half yard extra. For all those future tissue holders I make.
    Bad Spellers of the World
    U N T I E

  16. #16
    Super Member Girlfriend's Avatar
    Join Date
    Sep 2012
    Location
    San Clemente, CA
    Posts
    1,171
    Quote Originally Posted by Prism99 View Post
    Girlfriend, you're right on track. Half a yard would be 18", which is not enough. I always buy more than I think I will need to allow for crooked cutting and my mistakes, so I would up the yardage to 3/4 of a yard (24"). Although 5/8 of a yard is adequate (22.5"), it doesn't allow for mistakes. I always go up a little more and add any scraps to my stash.

    If you have a calculator, an easy way to figure out how many inches is in 5/8 of a yard is to do this: 36 times 5 divided by 8. The result is the number of inches in 5/8 yard. This works for all fractions because a yard is always 36.
    I've always wondered how to figure the number of inches in each of the cutting increments...the eights are the hardest to figure out. And yes, I usually had more yardage in case of mistakes, or if I have to prewash. Sounds like you have a degree in math, or you've worked in a quilt store. Thanks!

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

SEO by vBSEO ©2011, Crawlability, Inc.