A senior who bought decades ago and paid off the mortgage typically holds far more equity than the benchmark alone suggests, since years of principal paydown and appreciation both stack on top of each other, while a more recent buyer with a larger remaining balance holds proportionally less.
The honest way to find the real number is a hand-reviewed valuation of the specific property, not a citywide average, because renovations, lot size and condition move a home's actual value away from the benchmark in either direction.
Joel Dyck runs that valuation for seniors specifically to answer the equity question before any decision about selling gets made. Get your hand-reviewed valuation from Joel Dyck.