Old shingle weight

Does anyone have a rough idea of what the shingles weigh per square on a tearoff? Obviously this can vary a great deal for a lot of reasons. I am thinking a 3 tab roof that has lived its life. Granule loss and all

I would guess an average of around 200 lbs/sq for your basic 3-tabs.

thats exactly what I was guessing

Are you looking for a number to calculate disposal fees? If so, I’d pad it a little so as to not come up short. With shingles,edgings, valleys and underlayments I usually figure around 250 per square (per layer) to cover disposal