There are several factors that impact how much you can qualify for when you get a reverse mortgage.
The main factors are the age of the borrower (or youngest borrower if there is more than one), the interest rate of the reverse mortgage, and the appraised value of the home.
Generally speaking, the older you are, the lower the interest rate, and the higher the appraised value of the home, the larger a reverse mortgage a homeowner will qualify for.
The location of your property can also affect the amount you are eligible to borrow. HECM reverse mortgages have maximum amounts set by the government.
There are a few mortgage calculators online that may give you some idea of the amount you will be able to borrow.
The AARP reverse mortgage calculator can be found here.
A reverse mortgage calculator provided by the National Reverse Mortgage Lenders Association can be found here.
Bank of America offers reverse mortgages. Their reverse mortgage calculator is here.