Most reverse mortgage conversations start with a lender asking for your information. Ours starts with a calculator. The goal is simple: you should know roughly what the numbers look like before you ever talk to anyone.

Below is the calculator. Underneath it, the plain-English explanation of what each input means and why the output comes out the way it does.

What the calculator tells you

The output is called the Principal Limit. That is the total gross amount the HECM program is willing to advance against your home, given your age and your home's value. From that number, closing costs and any existing mortgage payoff come off the top. What remains is the Net Principal you can actually receive.

Think of the Principal Limit as the top of the funnel. Think of the Net Principal as the bottom.

The three inputs that matter

1. Age of the youngest borrower

The HECM formula is built around life expectancy. Older borrowers qualify for a higher percentage of their home value because the loan is statistically outstanding for a shorter time. A 78-year-old qualifies for a higher percentage than a 63-year-old. If you are married, the younger spouse's age drives the calculation.

This is why a one-year difference can matter. Waiting from 62 to 63, or 67 to 68, bumps your access up in a predictable way.

2. Appraised home value (up to the HECM lending limit)

The calculation uses the lesser of your home's appraised value or the federal HECM lending limit for the current year. The lending limit is updated annually by HUD. If your home is worth more than the limit, the portion above the limit does not count toward your Principal Limit.

This is where many higher-value homeowners look at a jumbo reverse or proprietary reverse option instead. We can walk through that in a phone call if your home value is well above the HECM cap.

3. Existing mortgage balance

If you have a regular mortgage on the home, it must be paid off at closing using HECM proceeds. That is fine — it is the whole point for many borrowers. But it reduces the Net Principal you walk away with.

If your existing mortgage is small, more cash is available. If it is large, most of the HECM may go toward paying it off, with little or nothing left over. Both outcomes can still be worth it — eliminating a required monthly mortgage payment is a meaningful win on its own — but you should know which scenario you are in.

The Principal Limit Factor, explained

The percentage of home value you can access is called the Principal Limit Factor, or PLF. HUD publishes PLF tables that lenders use to quote your number. The PLF is a function of:

• The age of the youngest borrower.
• The expected interest rate at the time of application (higher expected rates reduce your PLF).

Because the expected rate moves with the bond market, PLFs move too. A quote today and a quote a month from now may differ. That is normal. Call for current rates when you are ready to commit to numbers.

What you see vs. what you actually get

Three things come out of the gross Principal Limit before cash reaches you:

1. Upfront mortgage insurance premium (a percentage of the home's appraised value) — this is what pays for the FHA non-recourse protection.
2. Origination, appraisal, title, and counseling costs.
3. Payoff of any existing mortgage on the property.

What remains can be taken as a lump sum, a monthly tenure or term payment, a line of credit, or any combination. A HUD-approved counselor will go through every option with you in detail.

Why two calculators can give two answers

If you use another lender's calculator and it shows a different number, it is almost always because of one of three things: a different expected rate, a different lending limit (some calculators do not update annually), or a different assumption about closing costs. The underlying PLF tables are public, so any licensed lender using current HUD numbers will land very close to ours.

From estimate to real quote

The calculator is an estimate. A formal quote requires:

• A full credit pull and financial assessment.
• An FHA-approved appraisal.
• HUD-approved counseling.
• A locked expected rate.

The estimate is usually within a few percent of the final Principal Limit if the home value you entered is accurate. If you want us to refine the estimate with current rate assumptions, that is a 15-minute call.