Method for estimating yardage in odd balls?

Hi - Can anyone suggest a simple method to estimate the yardage in the odd balls of yarn I have, considering the weight of the yarn? I figure some smart knitter has figured out a rule-of-thumb or technique to help me. Thanks.

You can weigh it and divide the grams by the original gms in the skein, them multiply that percentage times the original yardage.

I’m talking about balls without the original labels. So I don’t have the weight, yardage, or anything to go by but the yarn itself. Other ideas that might make my big stash more useable? Thanks.

You can use a McMorran balance. It measure a small length of yard and you can calculate the yards per pound from the data.

You could also use a fishing line meteravailable at many fishing shops.

Measure the width of a chair back. Wrap the yarn around the chair back, counting the the number of loops. Double the number of loops and multiply by the chair width to get total inches, then convert that to yards and rewind the yarn into a ball again. It only takes about 10 minutes or less per ball.