I have found that the best use of a food scale is to weigh your yarn. (My friend the Weight Watchers instructor hates when I say this!) I purchased a digital food scale that displays both ounces and grams. They can be found at many large retail stores (Target, Walmart, etc.) and are fairly inexpensive.
When making socks out of a 100g skein, I place the yarn on the scale and keep winding a ball off of the skein until the scale shows 50g. Voila! I now have two 50g balls of yarn allowing me to knit two socks at one time without having to use both ends of the skein. (This can get a bit tangled and I don’t like anything to slow me down.)
I also use the scale to weigh completed socks to help me determine if I have enough yarn remaining to knit the second sock. For example, you knit a sock for a long foot and you are unsure if you need to purchase more yarn – weigh the completed sock and compare it to the weight of the yarn left over. If the completed sock weighs less than the weight of the remaining yarn then you will not need to purchase more yarn.
If you want to knit two socks at a time with a questionably short yardage amount – use the scale to divide the yarn evenly and knit two toe up socks until the yarn is gone.
I have been midway through a sweater project and not sure if I have enough yarn left to knit the last sleeve. I will just weigh the finished sleeve and compare that to the amount of yarn I have left. This has saved me from being a little short on yarn and then scrambling to find the right dye lot.
