How I measure for welt cord cut on the bias.

[gene]

It's great when you can cut 76" of bias strips for your fabric. (This is the longest length on a 54" bolt of fabric if you cut at a 45 degree angle.)

But sometimes I need to cut on the bias and I also need to conserve as much of the fabric as possible because I just don't have much excess fabric to waste.

This is how I figure out exactly how much fabric I need for my welt cord:

Example:

I have a sofa that needs 950" of welt cord. I am going to cut the fabric on the bias.

My fabric is 54" wide.

My welt cord strips of fabric will be 1 1/2" wide.

54" divided into 950" = 17.6

I need 17.6 strips of fabric. I round up to 18 strips of fabric.

18 x 1 1/2" = 27".

If I cut 27" of my 54" wide fabric, and cut this on the bias, I will have my 950" of fabric for my welt cord.

gene

[Mike8560]

I userstand fir  a full  strips at a 45• you need 950"  and get 27" out of it   
But you will have 2 triangle pieces one at each end do you not  you this material to make shorter strips ?
I no any strip shorted then say 30" would be silly  but  it would use less in a pinch.
I  don't use fabric much o. Boat unless it's inside  and not much inside work is done I Hesse it not that important to most  by the tine the insides bad they get a new boat   And the guy buying a older boat don't care so much   

[MinUph]

Gene,
  I just order enough fabric to accommodate bias welt. 1 1/2 extra for a chair and 3 for a sofa.

[sofadoc]

Those triangle pieces left at the end will usually do for something, such as a skirt flap, or a front arm panel.
Gene: Based on those figures, how long is your shortest strip?

[gene]

In this example I rounded up to a full 18 strips. This gives me extra inches. I do lose a few inches on each strip when I sew them together on the diagonal. I also only go down to about a 15" strip. What's left is the triangle you are talking about.

The thing to remember is the stretch on the bias. I have never gone short on welt cord with this method.

And, I certainly prefer to add yardage to the total to allow for the welt cord.

gene

[Cheryl]

Gene,  I have always found that since it stretches on the bias..  there is  ALWYAS way more than you  can mathematically account for.   

Nice formula. :-)