## Tutorial: Using ratios to calculate yardage

Posted by yarnberry on May 21, 2007

Sometimes I’m working on a project, and I want to figure out how many yards of yarn I’ve used to create it. I have to frog the project and measure it, or measure how many yards are left in the skein, right? There’s a much easier way: calculate how many yards I’ve used in the project, using the a kitchen scale and the yarn label.

Here is an example from a slipper pattern I’m working on at the moment. I want to make a second pair, but I’m not sure if I have enough yarn. The slippers shown here were made with a skein of Bernat Super Value Ombres, and I would like to make a pair out of some Schachenmayr Punto Shine.

- Measure weight of the object (without needles, buttons, or anything else attached):
- = 90 g

- Check weight of skein from the yarn label:
- = 142 g

- Calculate percentage of skein used:
- = weight of object / weight of skein
- = 90 g /142 g
- = 63%

- Check yardage of skein from the yarn label:
- = 275 yd

- Calculate percent of yardage used:
- = length of skein * percent of skein used
- = 275 yd * 63%
- = 174 yd

Remember that this is an *estimate*. The weight or yardage given on the label might not be quite right, your kitchen scale might not be balanced, you might have a slightly different tension when you make the object again with a different yarn. But it will give you a rough guideline of how many yards you need.

So I need approximately 176 yards of 18st/4″ yarn to make this project again. I only have 110yd of the Punto Shine, so I’ll have to use something else.

Some of you may be wondering why I don’t just calculate how much yarn I need by using the weights. I prefer to calculate project requirements using yardage because the weight of yarns varies so much by fiber content. I find that length requirements are more reliable.

## WTL said

It is like you are speaking another language, but adding in a touch of math to tempt me.

Evil.

## yarnberry said

We will get you crocheting any day now! Bwahahahaha.