Assessed Value vs. Market Value in California
Market value is what your home would sell for today. Assessed value is the taxable value your county uses — and in California that's set by Proposition 13, not the market. Your assessed value starts at your purchase price and rises no more than 2% a year, so the longer you own, the further it falls below market value. Your property tax is based on the assessed value — which is why two identical homes next door can have very different bills.
How big is the gap? Across 98+ California cities we compared, a typical existing owner is assessed about 38% below today's market value — in Irwindale the typical assessed value (~$187,000) sits about 71% under the ~$645,800 market value. That gap is the Proposition 13 tax break, and it only resets when the home sells.
Estimate your assessed value vs. market value
Enter what you paid, the year you bought, and the home's value today. We compound your purchase price by the official Proposition 13 inflation factors to estimate today's assessed value, then show the gap and the property-tax difference.
Estimated Proposition 13 assessed value today
$750,229
about 25% below the $1,000,000 market value ($249,771 lower)
Property tax at a typical 1.1% rate
On assessed value: $8,253/yr
If taxed at market: $11,000/yr
Proposition 13 saves about $2,747 a year
Estimate only. Assessed value is your purchase price compounded by the official Proposition 13 inflation factors (≤2%/yr); your county-enrolled base-year value may differ, and new construction or a remodel adds value. The 1.1% is a typical California ad-valorem rate (1% base + voter-approved debt); your area's rate and any Mello-Roos differ. Not an official bill.
Why California's gap is so wide
In most states the assessed value tracks market value fairly closely. California is different because of Proposition 13 (1978): it caps the taxable value at your purchase-year base plus at most 2% annually, regardless of how fast the market climbs. Decades of appreciation on a value that only grows 2% a year produces the large gaps below.
The gap resets at a sale
When a property is sold, it's reassessed to the new purchase price — so a new buyer's assessed value jumps up to market, while the long-time owner next door keeps a much lower one. New construction is reassessed too (the new part), and in a downturn a temporary Proposition 8 review can lower assessed value toward a fallen market.
The Prop 13 gap across California cities
Typical existing-owner assessed value (from the county roll) vs. market value (US Census ACS) for the cities with the widest gaps. The gap is how far below market a long-time owner's taxable value typically sits.
| City | Typical assessed | Market (ACS) | Gap below market |
|---|---|---|---|
| Irwindale (Los Angeles) | $187,000 | $645,800 | 71% |
| Courtland (Sacramento) | $232,000 | $645,000 | 64% |
| Inglewood (Los Angeles) | $323,000 | $744,300 | 57% |
| Maywood (Los Angeles) | $270,000 | $595,000 | 55% |
| Compton (Los Angeles) | $260,000 | $546,700 | 52% |
| Commerce (Los Angeles) | $288,000 | $583,200 | 51% |
| San Fernando (Los Angeles) | $316,000 | $630,700 | 50% |
| Hawthorne (Los Angeles) | $413,000 | $813,700 | 49% |
| Pico Rivera (Los Angeles) | $319,000 | $621,400 | 49% |
| Lynwood (Los Angeles) | $290,000 | $569,400 | 49% |
| Artesia (Los Angeles) | $395,000 | $763,700 | 48% |
| Walnut Grove (Sacramento) | $341,000 | $657,800 | 48% |
| South Gate (Los Angeles) | $316,000 | $608,500 | 48% |
| Alhambra (Los Angeles) | $431,000 | $812,700 | 47% |
| Baldwin Park (Los Angeles) | $309,000 | $588,100 | 47% |
| Bell (Los Angeles) | $300,000 | $561,400 | 47% |
| Huntington Park (Los Angeles) | $296,000 | $557,600 | 47% |
| South Pasadena (Los Angeles) | $832,000 | $1,545,100 | 46% |
| Carson (Los Angeles) | $351,000 | $645,600 | 46% |
| Hawaiian Gardens (Los Angeles) | $276,000 | $509,600 | 46% |
| Cerritos (Los Angeles) | $503,000 | $908,600 | 45% |
| Monterey Park (Los Angeles) | $453,000 | $818,300 | 45% |
| Whittier (Los Angeles) | $416,000 | $751,700 | 45% |
| Lawndale (Los Angeles) | $399,000 | $726,000 | 45% |
| Duarte (Los Angeles) | $391,000 | $710,700 | 45% |
| Bell Gardens (Los Angeles) | $292,000 | $527,900 | 45% |
| Rosemead (Los Angeles) | $411,000 | $729,600 | 44% |
| Gardena (Los Angeles) | $371,000 | $667,600 | 44% |
| La Puente (Los Angeles) | $332,000 | $593,200 | 44% |
| Pomona (Los Angeles) | $321,000 | $569,600 | 44% |
Assessed = median single-family Proposition 13 value for existing owners (county Assessor roll). Market = median owner-occupied home value (US Census ACS 5-year 2023). Cities where ACS top-codes value at $2M+ are omitted. A typical comparison, not your parcel's figures.
Frequently Asked Questions
What is the difference between assessed value and market value in California?
Market value is what your home would sell for today. Assessed value is the taxable value the county assessor uses — and in California it's set by Proposition 13, not the market: it starts at your purchase price and can rise no more than 2% a year while you own the home. So the longer you've owned, the further your assessed value falls below market value. Your property tax is based on the assessed value, not the market value.
Why is my assessed value lower than market value in California?
Because of Proposition 13. Your assessed (taxable) value is frozen to your purchase price plus at most 2% a year, while market prices have generally risen much faster. Across the 98+ California cities we compared, a typical long-time owner is assessed roughly 38% below what the home is worth today — and more in long-held neighborhoods. The gap only resets when the property is sold or substantially rebuilt (a reassessment).
Which is higher, assessed value or market value?
For most existing California owners, market value is higher than assessed value — often far higher — thanks to the Proposition 13 cap. The exception is a recent purchase (assessed value ≈ what you just paid) or a market downturn, where a temporary Proposition 8 'decline-in-value' reassessment can push assessed value below a now-lower market.
Does assessed value or market value determine my property tax?
Assessed value. Your annual property tax is the assessed (taxable) value times your area's rate — about 1% to 1.25% in most of California (the 1% Proposition 13 base plus voter-approved debt). Market value does not directly set your bill; it only matters at a sale, which resets the assessed value to the new price.
How do I find my home's assessed value vs. market value?
Your assessed value is on your annual property-tax bill and your county assessor's parcel lookup. Market value is an estimate — from a comparable-sales analysis, an appraisal, or an online estimate. Use the estimator above to approximate your Proposition 13 assessed value from your purchase price and year, then compare it to today's market value.
Learn More
California-specific educational overview, not an appraisal or tax advice. Assessed values are existing-owner Proposition 13 medians from the county Assessor roll; market values are US Census ACS estimates — both are typical figures for a city, not your parcel. Confirm your own assessed value with your county assessor and tax bill.