California Property Tax Calculator

How California property taxes actually work

California property taxes are different from most other states, and that difference comes down to one law: Proposition 13. Passed by voters in 1978, Prop 13 set the base property tax rate at 1% of a property's assessed value and capped annual increases in that assessed value at 2%. In practice, this means your tax bill is tied to what you paid for the house, not what it's worth today.

Here's a concrete example. Say you bought a home in San Diego for $750,000 in 2024. Your neighbor bought an identical house next door in 2015 for $450,000. Even though both homes are now worth $750,000 on the open market, your neighbor's assessed value is about $538,000 (the original $450,000 grown by 2% per year for nine years). At the 1% base rate, your neighbor pays about $5,380 per year while you pay $7,500. Same house, same street, different tax bills. That's Prop 13 at work.

The base 1% rate isn't the whole story, though. On top of that, most areas tack on voter-approved bonds and school levies. These push the effective rate to somewhere between 1.03% and 1.25% for most counties. The calculator above lets you select your county to auto-fill an estimated rate based on typical voter-approved bond levies for that area. On top of that, newer communities with Mello-Roos (Community Facilities District) charges can add another $500 to $10,000 per year in flat assessments that fund infrastructure like roads, parks, and fire stations. Mello-Roos charges are parcel-specific and not included in the county estimates, so check your county assessor's website for those.

What Prop 13 means for you over time

The 2% annual cap on assessed value increases is Prop 13's biggest benefit for homeowners. It makes your future tax bills predictable. Even if your home doubles in market value over 15 years, your assessed value only grows by 2% each year. That means a $750,000 purchase would have an assessed value of about $914,000 after 10 years and roughly $1,359,000 after 30 years. Compare that to a market value that could easily be $1.5 million or more in 10 years, and you can see how much Prop 13 saves long-term owners.

There is a flip side. When you sell and the new buyer takes over, the property gets reassessed at the purchase price. So the tax savings you accumulated don't transfer to the next owner. This is also why property taxes can feel like a shock when you move within California. You might be selling a home where your assessed value was far below market and buying a new one that gets assessed at full purchase price. The mortgage calculator can help you see how your new property taxes affect your total monthly payment.

The Prop 13 Projection tab in this calculator shows you exactly how your assessed value and tax bill grow year by year, and compares that to what you'd pay if taxes were based on market value instead. Try adjusting the annual increase rate below 2% if you want a conservative estimate. In rare deflationary years the increase has been less than 2%, though the full cap has been applied in most years since Prop 13 took effect.

Prop 19: how inheritance and moving affect your tax base

Proposition 19, passed by California voters in November 2020, changed two major pieces of property tax law. The first affects people who inherit property. The second helps homeowners 55 and older (or those who are severely disabled or displaced by a disaster) keep their low tax base when they move.

Inheriting a home after Prop 19

Before Prop 19, California's old rules (Propositions 58 and 193) let children and grandchildren inherit a parent's or grandparent's low assessed value on any property, regardless of whether they lived in it. That meant a child could inherit a rental property assessed at $200,000, keep that low assessment even though it was now worth $1.2 million, and continue paying taxes on $200,000. That loophole closed on February 16, 2021.

Under Prop 19, only a family home (the parent's primary residence) or a family farm qualifies for the inherited tax base, and only if the child moves into the home as their own primary residence within one year of the transfer. Investment properties, vacation homes, and rentals no longer qualify. They get reassessed at current fair market value when transferred.

Even for qualifying primary residences, there's a cap. The exclusion applies to the parent's factored base year value (the original assessed value grown by the 2% annual cap) plus $1 million. That $1 million figure is adjusted every two years for inflation and sits at $1,044,586 for transfers between February 16, 2025 and February 15, 2027. If the property's current market value exceeds the parent's factored base year value by more than that cap, the excess gets added to the new assessed value.

Here's a practical example. Say a parent's home has a factored base year value of $300,000 and the property is worth $1.8 million at the time of transfer. The gap is $1.5 million. The exclusion covers $1,044,586 of that gap, so the remaining $455,414 gets added to the child's assessed value. The child's new assessed value would be roughly $755,414, not the full $1.8 million and not the parent's $300,000 either. If the child does not move in within one year, the property gets reassessed at the full $1.8 million. You can model this scenario in the Prop 19 Transfer tab above.

Portability: taking your tax base with you

The other half of Prop 19 expanded a benefit that previously existed under Propositions 60 and 90 but was limited to one use and restricted to certain counties. Now, homeowners 55 or older and those who are severely and permanently disabled can transfer their current property's tax base to a replacement home anywhere in California, up to three times. Victims of wildfires or Governor-declared disasters can do the same with no limit on the number of transfers (one per disaster event).

The replacement home must be purchased or newly constructed within two years before or after the sale of the original home. If the replacement costs the same or less than the original, the old tax base transfers straight over. If the replacement costs more, the difference gets added to the old base year value. So someone selling a home with a $250,000 assessed value and buying a new home for $900,000 (where the old home sold for $800,000) would have a new assessed value of $350,000: the $250,000 base plus the $100,000 price difference. That's a significant savings compared to being assessed at the full $900,000 purchase price.

The portability claim must be filed with the county assessor within three years of purchasing the replacement home. This is a one-time filing per transfer, not an annual renewal. Use the Prop 19 Transfer tab to see how much the portability benefit could save you.

Supplemental tax bills: the surprise after closing

If you've just bought a home in California, you'll probably get a bill in the mail that you didn't expect. It isn't your regular property tax. It's a supplemental assessment, and it covers the gap between the old owner's assessed value and your new purchase price, prorated for however many months are left in the current fiscal year.

California's fiscal year runs July 1 through June 30. If you close escrow in October, the reassessment takes effect November 1 (always the first of the month following close of escrow), leaving 8 months in the fiscal year. The county calculates the difference between old and new assessed values, applies the 1% base rate to that difference, and prorates it for 8 out of 12 months. That's your Bill 1. For a $250,000 increase in assessed value, that works out to about $1,667 ($250,000 x 1% x 8/12).

Things get more complicated if you close between January and May. In that case, you'll receive two supplemental bills. Bill 1 covers the prorated months remaining in the current fiscal year. Bill 2 covers the full next fiscal year (because the new annual tax roll hasn't caught up yet). This can be a substantial amount, especially on high-priced homes. Someone buying a $1.2 million home where the prior assessed value was $600,000 could owe $6,000 or more in supplemental taxes.

One important detail: supplemental bills arrive separately from your regular annual tax bill. They are not paid through your mortgage escrow or impound account. You pay them directly to the county tax collector. Many first-time buyers in California are caught off guard by this, so it's worth factoring supplemental taxes into your home-buying budget.

Exemptions that can lower your bill

California offers a few property tax exemptions, and the most common one is the homeowner's exemption. If you live in the home as your primary residence as of January 1, you can file a one-time claim with your county assessor to reduce your assessed value by $7,000. At a 1% base rate, that saves roughly $70 per year. It's not life-changing, but it's free money you should claim if you haven't already. The exemption automatically renews each year once filed.

The disabled veteran's exemption is much larger. Veterans rated 100% disabled (or compensated at 100% due to unemployability) can reduce their assessed value by roughly $180,000 in 2026 under the basic tier, or about $271,000 under the low-income tier if household income falls below roughly $81,000. These amounts are adjusted each year for inflation and published by the Board of Equalization in late fall.

Starting in 2025, SB 23 introduced a full property tax exemption for 100% disabled veterans on their primary residence. This zeroes out the entire tax bill. It's set to remain in effect through 2035, though future legislation could extend or modify it. If you're an eligible veteran, this is one of the most valuable property tax benefits in the country. Toggle it on in the calculator to see the impact.

What this calculator covers (and what it doesn't)

The county-level rates in this calculator include the 1% Prop 13 base rate plus typical voter-approved bond levies for your area. For most California homeowners, this covers the largest portion of the tax bill. The county estimates are derived from county auditor tax rate area data and U.S. Census ACS figures, calibrated against actual Tax Rate Area schedules published by county assessors. They represent what a typical new buyer would pay before any parcel-specific charges.

What the estimates do not include: Mello-Roos (Community Facilities District) special taxes, city parcel taxes, and special assessments for things like flood control, mosquito abatement, or transit. These charges are set per parcel, not as a percentage of assessed value, so they can't be estimated with a county average. In older neighborhoods they may add only a few hundred dollars. In newer communities with active Mello-Roos bonds, they can add $3,000 to $10,000 or more per year.

Rates also vary within each county depending on your exact Tax Rate Area (TRA), which is determined by your address and the specific combination of taxing districts you fall within. For example, in San Diego County the TRA rate ranges from 1.05% in Coronado to 1.27% in Lemon Grove. The county estimate in this calculator represents a typical midpoint. To find your exact TRA rate, look up your parcel on your county assessor's or tax collector's website. Use this calculator as a solid starting point, then layer in your specific TRA rate and any Mello-Roos charges for a complete picture.