# Which yarn should I use?

In this challenging economy, we all need to save pennies wherever we can. One of my money-saving techniques is to knit from my stash whenever I can.

 So much yarn, so little time!

A few years ago, when the money was flowing a little faster, I changed my stash acquisition methods from buying a couple of skeins here and there to buying sweater-quantity. This really helped my stash grow from "What can I do with 400 yards of this yarn?" to "Which sweater do I want to knit with this yarn?" A much better place to be for this sweater knitter!

This approach means that I need to substitute yarns quite a bit. A calculator is my best friend in these cases, as well as knowing the math for calculating yarn substitution, of course.

Vicki Square's book The Knitter's Companion is a favorite of mine, and it contains a section on calculating yardage for yarn substitution. Here it is:

Formula for Interchanging Yarns

Yarns of similar weight and similar texture can generally be interchanged effectively. But there can be a large range in length between balls of two different yarns of the same weight, depending on the fiber type, number of plies, and tightness of the twist.

The number of balls required times the number of yards (or meters) per ball = total number of yards (or meters) needed.

The total number of yards (or meters) needed divided by the number of yards (or meters) in one ball of substitute yarn = number of balls needed of substituted yarn.

For example, if 12 balls of the required yarn have 145 yards (133 meters) each, then the total number of yards (meters) you'll need is:

12 balls x 145 yards = 1740 total yards.

If you want to substitute a yarn that has 163 yards (149 meters) per ball, then you'll need:

1740 total yards / 163 yards = 10.67 balls.

Because you must buy full balls of yarn (and because it's always a good idea to have a little extra yarn) you'll want to buy 11 balls of the substitute yarn.

—Vicki Square, The Knitter's Companion

If you're in a yarn shop and you need to figure this out, don't forget about the calculator on your phone! I use mine all the time for "knitting math."

This handy formula is just one of hundreds of helpful bits of advice for knitters in The Knitter's Companion. Get your copy now—it's on sale for less than half-price!

Cheers,

P.S. Do you have a favorite knitting book? Share it with us in the comments!