If you're buying new yarns for a multicolor project like the About Town Shawl, you can simply choose colors you love and get started without being too concerned about yardage, as long as each skein has at least as many yards as the pattern says you'll need.
But what if you want to use up some of those partial skeins of yarn in your stash? You'll need to be sure you have enough of each color. It's not difficult to figure that out, and in this post, I'll explain how.
You'll need a scale that allows you to weigh in grams (I use a simple kitchen scale), a calculator (or Excel, or old-fashioned pencil and paper and your awesome math skills), and the yarn label. Don't have the label anymore? Look up the yarn on the yarn company's website or in Ravelry's yarn database. (If you aren't sure what yarn it is, can you remember what project you used it for? You may have recorded the yarn on your Ravelry project page, so check that.)
From the yarn label or other source, gather two key pieces of information: 1) how many yards are in a skein, and 2) how many grams does the skein weigh. Write those two numbers down and let's get started!
As an example, I'll use the leftovers from a skein of The Fawn and The Fox Badger sock yarn, in the Fantastic Mr. Fox colorway. The label says the original skein weighed 100 grams, and had 464 yards. To calculate how many yards remain, first divide the number of yards in the original skein by the number of grams in the original skein. In my example, 464 yards divided by 100 grams equals 4.64. Now I know that there are 4.64 yards per gram.
Next, weigh the partial skein, then multiply its weight in grams by the number of yards per gram. The result is the number of yards left in the partial skein.
My yarn weighs 26 grams; 26 grams x 4.64 yards/gram = 120.64 yards. See how easy that is?
Now you're all set to go stash diving and see if you already have some lovely yarns with enough yardage to make the shawl. Have fun!
Just a reminder — tomorrow's the last day of the introductory sale on the About Town Shawl. Save 25% in my Ravelry pattern store with the coupon code SHAWL25. The sale ends at midnight EST April 19.