The dreaded Stock Take!!!

If you have full rolls of the same material could you weigh them both and figure the remaining material from the difference?
On the other hand, you could give this a go:
https://handymath.com/cgi-bin/rollen.cgi?submit=Entry

 

https://www.signcraft.com/online-exclusives/2017/05/how-much-vinyl-is-left-on-that-roll/ this is the best way if you need an accurate count.

You can't just eyeball it? we have probably 100-150+ open rolls at a time of material... our inventory consists of "Yeah.. looks like theres 20 FT, or 50 Ft.. or 100 ft" only the $1500-2000 roll stuff do we end up doing a more accurate count on.

 

Cool, I didn't know this existed - I created my own formula for doing this, mine is pretty darn close to this calculator, but not exactly. My method does work well - I do it all the time to see if I have enough on a scrap roll to do a small job.

This requires a digital caliper
1. With the digital caliper, set it to mm. Measure the Thickness of the material left on the roll - minus the core. (call this number A)
2. measure the thickness of the material - just one layer this time. (Call this number B)
Divide: A/B = C
Now take C and multiply by 11 (the usual diameter of the core). Divide that by 12 = equals how many feet are left on that roll. I always subtract 3 (ft) from that for a little cushion.

I really like that calculator you shared though... I'm going to book mark it and try it!

 

Here are a few calculators to help you determine the length left on a roll:
https://www.firesprint.com/vinyl-roll-length-calculator.html

 

How many rolls is it, that you've been asked to calculate ??

 

That's just plain negligence. I'd make the clown who did all the careless ordering unroll the rolls, measure it and then label it. Your company has been slack on this and suddenly they want to be accurate ?? Poppycock. Sounds more like someone doesn't like you, unless you're the one who did all the needless ordering. When you say all the rolls inside the building..... how many are outside ??

 

I find it fastest to weigh it. Don't forget to minus out the weight of the core.