| Rudy Flores · (619) 392-6714 · Real Estate Strategist, Realtor® · CalDRE #02257808 · Responsible Broker CalDRE #01481919
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Long-Held Home? See Your Equity Since Buying

Been in your home for years? Start with the price and year you bought to see today's estimated value, the equity you hold and your Prop 13 gap.

HOME TOOLS · OCTOBER 2026

If you have lived in your home a long time, you may be sitting on more equity than you realize, and paying tax on a much older value. This page starts with the price you paid and updates it by the change in Zillow's typical values for your ZIP code over all those years.

Whether you plan to stay for good or are starting to think about what comes next, the numbers help: value, loan, equity, a net after costs and the gap between market value and your Prop 13 value.

Your purchase
Values are Zillow's typical value for the ZIP code, not for your street.
Uses Zillow's series for that home type when the ZIP code has one for your purchase month.
From 1985. Before 2000 the estimate chains FHFA's yearly ZIP index to Zillow.
Starts at Zillow's typical single-family value in 91913 for June 2006; use your own price.
Your loan
Pick the second choice if you refinanced or have a home equity line.
Used with the first choice. Enter 0 for a no-down-payment loan.
Blank uses the Freddie Mac average for the month you bought (15-year average for a 15-year term from August 1991).
The loan you took out when you bought.
Used with the second choice: from your latest statement; include any home equity line.
Today
Moves the range around the estimate, the same rule of thumb as the home value range tool.
Commission, escrow, title and transfer taxes, as a share of the price; commission is negotiable.
Leave at 0 to estimate it from your price and the State Board of Equalization's yearly factors.

Staying for good, downsizing or helping family? The Home Strategy Quiz takes only four questions, and Rudy's reply is a plan for your situation.

Take the Home Strategy Quiz

Talk to a lender. Rates, loan programs and approvals come from lenders, not from websites or real estate agents. Talk to your own mortgage broker, or use our preferred lender, Point Mortgage Corporation (NMLS #231073), at (619) 475-4095. You are always free to choose any lender you like, and you can verify any lender’s license at nmlsconsumeraccess.org.

This is an estimate for planning, from Zillow's ZIP-wide typical values applied to your purchase price. It is not an appraisal, a broker price opinion, an offer, a loan offer, or tax or legal advice, and Rudy is a real estate agent, not a lender, appraiser or tax professional.

How the estimate works

  1. We check the Zillow index for your home type and ZIP code at your purchase month and at the latest month; before 2000, FHFA's yearly ZIP index fills in.
  2. That change is applied to what you paid, and the condition you choose sets the range.
  3. If you still carry the purchase loan, its balance follows the regular fixed-rate payments from the month after you bought.
  4. Equity is the midpoint less any loan; deduct selling costs as well and you get a net before tax.
  5. Your Prop 13 estimate compounds the price you paid by the Board of Equalization's yearly factors, each one 2% or less.

Your Prop 13 value and Prop 19

For long-time owners, the Prop 13 gap is often the surprise. Your taxable value started with what you paid and has been allowed to grow only 2% or less per year, so after many years it can sit well below market value.

At 55 or older, Proposition 19 may let you keep that lower taxable value when you move, wherever in California your next home is, if you buy it within two years of selling. It works up to three times; confirm eligibility with the county assessor.

If staying for good turns into a smaller home, start with the downsizing calculator.

Sources and dates

Questions owners ask

I bought before 2000. Does this still work?

Usually. Zillow's ZIP data starts in 2000, so earlier purchases use FHFA's yearly ZIP index to reach Zillow's first full year. A few ZIP codes lack the older index, and the page says so.

How far off could this be?

A ZIP-wide index cannot see decades of upkeep, additions or a remodel, so a long-held home can land outside the range. Rudy reviews recent nearby sales for free for a real value.

My home is paid off. What do I pick?

Choose "No loan (paid off or paid cash)." If you have a reverse mortgage or an equity line, pick the second option and enter that balance instead.

Is my Prop 13 value my home's value?

No. It is the base your property tax uses, which started at your purchase price and rises 2% or less a year; after a long time it is often far below market value. Your tax bill shows the exact figure.

More from Rudy

Want a Real Number?

Rudy will look at recent sales near you and talk through your equity, your Prop 13 picture and the choices ahead.

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