For every pattern I design I need to figure out how much yarn is required to make it. Usually what that boils down to is knitting a swatch and then ripping it out so I can measure it. Before ripping out the swatch (which is knit to my predetermined gauge) I measure it and take note of the number of stitches and rows. This swatch is knit in the round because the final project (gloves) is also knit in the round. Sometimes gauge can differ when working in the round or working flat.
I measure the amount of yarn required to knit the swatch. I have a handy dandy yarn meter for doing this. I measure it at least five times and then take an average. This swatch took 54 feet of yarn.
I also weigh the yarn and then throw all the numbers into a spreadsheet I’ve developed for calculating yardage. It gives me the amount of yarn required to knit one square inch of fabric. In this case it’s 41.8302 inches. I compare my findings for both the yardage calculations based on weight and those based on length to make sure I haven’t made an error somewhere.
Then I figure out how many square inches of fabric are required to make the project. In the case of a sweater it’s easy because it’s mostly comprised of squares and rectangles. For instance, a baby sweater back is about 10″ wide by 10″ long. 10×10=100 so the sweater back is 100 square inches. It would take 4183.02 inches or just over 116 yards of yarn to knit the back of the sweater. Gloves are a little trickier because of all those fingers, but it still boils down to dividing the project up into rectangles.
This is what remains of my swatch after establishing yardage.