Seriously if you want to know how many you own, count them.I have counted my LPs many times. I still own about 2,800. I use to own 4000, and before that 6000, and before that 13,000.Best to really just count jackets. not individual LPs. One cover is one album (no matter one Lp or 2 or even 3), sets count as one.I use a sheet, and mark down each bin quantity on the sheet. then add up the paper numbers.
I can say trying to estimate is usually off by 20% Unless you are really really good at it.