From grams to length
Estimated meters = remaining grams × label meters ÷ label grams. For 37 g of a yarn labeled 100 g / 240 m, the result is 88.8 m, or approximately 97.1 yd. One yard equals 0.9144 meters.
Zero remaining weight gives zero length. A remaining weight greater than one full package can represent several partial balls of the same yarn. Don't combine unlike yarns under a single label ratio. Label values and weighing precision make this an estimate.