How much fabric needed for binding?

That’s the question I get asked often.
It depends on what kind of binding you are doing but here is what I do most of the time.
 
To specify, my main bindings are made as

• double fold
• straight grain
• same fabric

I use double fold because it is far easier and quicker to make than the single one. Cut the fabric and fold in half on length way. To confess, I don’t even iron(if you are not sure, do iron). Also it gives extra layer of fabric to cover the edge of quilt.
I rarely make curved edge and bias bindings are for curved edges.
Yes, scrappy bindings are pretty but that doesn’t happen very often to me.

I actually attached straight binding to these, because those curves were quite gentle and it went fine.

How wide to cut the fabric.

I cut 2″ wide for 1/4″ wide finish.
If you want to make anything wider, here is the math.

Multiply your chosen binding finish width by 6 and add 1/4″ to 1/2″.

You need to multiply by 6 because that’s the number of layers going to be on the edge and extra 1/4″ to 1/2″ is for the thickness of quilt and that is quite plenty.

 

How much fabric?

• Find a perimeter of your quilt.

For example this ‘Fox and Geese’ is 40″ by 40″ and that makes the perimeter 160″.

‘Fox and Geese’

This ‘Stained glass medallion’ is 58″ by 58″ and the perimeter is 232″.

‘Stained glass medallion’

• Divide the perimeter by 40.

The ‘Fox and Geese’ gets 4 and the ‘Stained glass medallion’, 5.8 and that needs to be round up to 6. Always round up to the nearest.

The reason : If binding tape strips are cut from full width of fabric, 42″ to 44″ and cutting off selvages, stitching strips together on diagonal way and turning the corners, each strips become a bit longer than 40″. So the result of division by 40 will give you how many strips to be cut to make a binding for a quilt(Yes, the binding for “Fox and Geese” was quite tight but it had just enough!)

• And now, multiply width of binding and the result of division.

‘Fox and Geese’ : 2″ * 4 = 8″ … 1/4 yard or 9″

‘Stained glass medallion’ : 2″ * 6 = 12″ … 1/2yard or 18″

 
Then you have how much fabric you need for a binding.
Hope that helps!