How do I determine how much yarn I will need to buy for a project?

This is one of the reasons you should make a swatch as so many patterns direct (by including gauges) but so few people actually do. Not only does it determine how your crochet tightness or looseness compares with that of the pattern-writer, but it also allows you to calculate how much yarn you will need for an entire project.

 

How does it do that? What size is your swatch? It should be at least 5 by 5 inches for accurate measurement, for one. Divide the full area of your project by the area of your gauge swatch. Then, weigh your swatch on an ounce scale and multiply that weight by the number you received before. Add another ounce or two for ends, joining skeins, and for finishing (a term used to refer to sewing up the project, adding buttons, hiding ends, et cetera.) The larger the project, the more "extra" yarn you will need to finish your project.

 

You could just go with the basic number before you add one or two ounces, but you run the risk of running out. Though you will probably have extra yarn left over when you add one or two ounces to the total, at least you will have had enough yarn to complete the project.

 

 

For example, if you have a 5 by 5 inch swatch that weighs 1/2 an ounce and your full project is 200 square inches, 100 square inches divided by the 25 square inch gauge size is 4; multiply that by the 1/2 ounce weight of the swatch and get 4—you will probably need 5 ounces of yarn for your full product.