PDA

View Full Version : How do you calculate yardage needed?

Arugula
01-29-2006, 10:56 AM
Okay, supposing I wanted to make a skirt I designed. How would I figure out how much yardage I needed? For example: I mapped out a skirt that is 18" at the waist (sits low on hips), 30" at the hem and 20" long. I multiplied 20x30 (thinking it was easier to figure the area of a rectangle than a trapazoid and I could somehow find a use for extra yarn :lol:) and got 600. Then divided it by 36 to get yardage instead of inches. Got 16.66. There is no way I can make the front of a skirt with 17 yards of yarn. Gauge would be 4-5 sts per inch. What am I doing wrong?

Vendie
01-29-2006, 11:37 AM
Are your measurements just for one side of the skirt? Is 18" all the way around or just the front? If it's just half, that one thing you need to add in. Also, you're probably going to need your row gauge too - how many rows per inch you're going to have.

You'll probably need to approach the math a little differently, starting with your stitch and row gauges. Unfortunately, since I have never done this, I'm having a hard time coming up with the formula. But I would venture a guess that your required yardage is going to be closer to that a sweater.

Ingrid
01-29-2006, 11:44 AM
Maybe you could find a similar pattern and get the approximate yardage from that.

Arugula
01-29-2006, 11:59 AM
I am so retarded, I was reading Knitting Without Tears, my mind ruminating on my bad math, when it hit me that the inches in the pattern are KNITTED inches, not straight from the skein flat yarn inches. Duh. That said, I will now read the responses.

Arugula
01-29-2006, 12:01 PM
I'm thinking that if I can duplicate the gauge with something I already have and then unravel it and measure, that I can estimate the yardage required based on that. I wish there was an online calculator, though, I am supremely lazy.

sogrammatical
01-29-2006, 12:02 PM
What you've calculated, I believe, is the square yardage of the actual skirt - the area, assuming it's a rectangle.

I've thought about it a bit, and here's how I think you'd find the necessary yardage for your skirt. I've just picked numbers randomly - to actually calculate this, you'll need to do some measuring.

Let's say your yarn knits up at 5 stitches and 5 rows per inch (I'm just picking easy numbers). At this point, you need to find out how much yarn per stitch. I imagine for this part, you'll just have to knit up a bit and then frog it, taking care to note where a row starts and ends, measure it, and then divide to get yard (or inch) per stitch. You could do this from your swatch once you've measured it for gauge. Let's say 150 stitches (the number in your width, assuming a rectangle) is 5 yards.

So now you know how many yards of yarn per row of your skirt. Here's where the row gauge is used. At our assumed 5 rows per inch and 20 inches of skirt, that's 100 rows for the skirt. At 5 yards of yarn per row, that makes 500 yards for the skirt.

Does this seem like a reasonable method to anyone else? I've got a lot more experience in the math field than the knitting field so it's hard to say if this will actually work.