Figure out how much stash yarn you have by weighing it! Use this simple kitchen scale to calculate your approximate yardage.
Great video explanation on how to estimate by weight from Andrea Rangel here.
Bamboo Digital Electronic Kitchen/Food/Crafting Scale
Takes 2 AAA Batteries (Not included)
Rectangle Scale Measures in Grams, Pounds and Ounces, kg
Measures 9 inches by 6 1/2 inches.