How to calculate property tax in California: the complete guide

Last updated 2026-07-09

What is the basic formula for California property tax?

Your annual bill equals your assessed value times the total tax rate for your specific tax rate area (TRA). That is the whole formula.

Assessed Value × Total Tax Rate = Annual Property Tax

The total rate has two parts. The first is the 1% general levy that California's Constitution Article XIII A (Proposition 13, passed in 1978) sets as the statewide floor and ceiling for general-purpose tax. ^[1] The second is a stack of voter-approved debt levies added on top: school bonds, community college bonds, flood control, library improvements, and the like. Those extra levies change from county to county and from parcel to parcel.

A homeowner in a heavily bonded part of Los Angeles might pay an effective 1.25%. Someone in a lightly bonded pocket of the same county pays 1.05%. Neither number is a mistake. They just sit in different tax rate areas.

Your exact TRA and its rate show up on your county assessor's or tax collector's website, and on the tax bill itself. The TRA number is printed on every California property tax bill.

How does Proposition 13 set the assessed value used in that formula?

Proposition 13 is the one thing that makes California's property tax unlike any other state's. It deserves real attention.

Prop 13 tied assessed value to what you paid, not to what your house is worth this year. The technical term is your "base year value," set when a change of ownership or new construction happens. ^[1] Once that base year value is locked in, the assessor can raise it by no more than 2% a year, or the California Consumer Price Index change, whichever is smaller.

The California State Board of Equalization publishes the annual inflation factor. For fiscal year 2024-25 the Board set the maximum increase at 2%, the statutory ceiling, because CPI ran higher than 2%. ^[2] For 2023-24 it was also 2%. In several years between 2010 and 2021 the factor came in well under 2%, and one year it was 0%.

Here is what that does in practice. A homeowner who bought in 2005 for $500,000 has an assessed value today no higher than $500,000 × (1.02)^20, which is about $742,000, no matter what the house would fetch on the open market. The neighbor who bought the same model in 2023 for $1,200,000 gets assessed at $1,200,000. Same house, very different bills. That is Prop 13 doing exactly what it was written to do, and it is not an error on your bill.

Inherited the house through a parent-child transfer? Proposition 19 (effective February 16, 2021) rewrote those rules. The full exclusion now applies only if the child moves in as their primary residence, and the exclusion is capped at $1,000,000 above the parent's assessed value. ^[3] Properties that miss those tests get reassessed to market value.

How do I find my assessed value and total tax rate?

Three sources work, and all three are free.

Start with your annual property tax bill from the county tax collector. It lists the assessed land value, the assessed improvement value, any exemptions subtracted, the net taxable value, each levy line by item (1% general, bond A, bond B, and so on), and the total due. Read it top to bottom once and the formula stops being mysterious.

Next, your county assessor's public records portal. Every California county assessor posts assessed values online. Search by address or APN (assessor's parcel number). The assessor's office sets the value. The tax collector's office bills you off of it.

Third, the California State Board of Equalization's county tax rate publications. The BOE puts out annual reports listing every tax rate area in every county and the levy breakdown inside each one. ^[2] They are public and free at boe.ca.gov.

In Los Angeles County, the Office of the Assessor runs a searchable portal where you can pull any parcel's assessed value and tax rate area. Santa Clara County's assessor does the same. ^[5] San Mateo County's tax portal and Contra Costa County's system work the same way. Own property in any of those counties, and the county website is the fastest route to a precise number.

Can you walk through a real worked example?

Sure. Take a home bought in Sacramento County in 2022 for $650,000.

Step 1: Set the base year value. The purchase price is the base year value: $650,000. ^[1]

Step 2: Apply the annual inflation adjustments. The 2023-24 inflation factor was 2.00% and 2024-25 was 2.00%. So the 2024-25 assessed value is $650,000 × 1.02 × 1.02 = $676,260.

Step 3: Subtract exemptions. This owner qualifies for the California Homeowners' Exemption, which knocks $7,000 off assessed value. ^[6] Net taxable value: $676,260 − $7,000 = $669,260.

Step 4: Multiply by the total tax rate. Say this parcel's TRA carries a total rate of 1.1516% (a real Sacramento County rate). Annual tax: $669,260 × 0.011516 = about $7,706.

That is the bill. The tax collector splits it into two installments. The first covers July 1 through December 31, is due November 1, and goes delinquent December 10. The second covers January 1 through June 30, is due February 1, and goes delinquent April 10. ^[7]

The "10-10" delinquency dates hold across all 58 California counties. Memorize them if you own here.

What local add-ons push the rate above 1%?

Everything above 1% on your bill is a voter-approved debt levy. The 1% base itself goes entirely to local government (cities, counties, schools, special districts), split up by a formula in state law.

Common line items:

• Unified school district bond measures (often 0.03% to 0.08% each)
• Community college bonds (similar range)
• County flood control bonds
• Library improvement bonds
• Fire protection or emergency services measures
• Mello-Roos Community Facilities Districts (CFD) charges, which get big in newer subdivisions

Mello-Roos deserves its own flag. A CFD levy is technically a special tax, not an ad valorem property tax, but it lands on your tax bill and can add hundreds or thousands of dollars a year in newer master-planned communities. California Civil Code Section 1102.6b makes sellers disclose CFD status to buyers. ^[8] Shopping for a home and the effective rate on a new subdivision looks like 1.8%? Mello-Roos is almost always the reason.

The statewide average effective property tax rate was roughly 0.75% of market value as of 2023, per the Lincoln Institute of Land Policy's 50-State Property Tax Comparison. ^[9] That sits below the 1%-plus statutory rate because Prop 13 holds assessed values far under market on long-held homes, which drags the average way down.

What exemptions reduce the taxable assessed value?

A few California exemptions cut the assessed value before the tax rate ever touches it.

Homeowners' Exemption: $7,000 off assessed value for owner-occupied primary residences. At a 1.1% rate, that saves about $77 a year. Small, but free. File once with your county assessor and it renews automatically. ^[6]

Disabled Veterans' Exemption: $100,000 to $150,000 off assessed value for qualifying disabled veterans, adjusted periodically for inflation. The larger figure applies to lower-income claimants and 100% disabled veterans. ^[6]

Church, Religious, and Charitable Exemptions: Qualifying non-profit property used only for exempt purposes can get a full exemption. The California BOE administers this through the county assessors. ^[2]

Base year value transfers under Proposition 19: Prop 19 (effective April 1, 2021 for these transfers) lets homeowners 55 or older, severely disabled homeowners, and disaster victims move their existing base year value to a replacement home anywhere in California, up to three times. ^[3] That is a real upgrade from the old Prop 60/90 rules, which were county-specific and one-time only.

None of these are automatic except the Homeowners' Exemption, and even that only auto-applies in some counties after a recorded deed. Do not assume. Call your county assessor and confirm.

How can I tell if my assessed value is too high?

This is the question that matters if your bill just shocked you.

On long-held property, the assessed value is almost never too high. Prop 13 keeps it anchored to purchase price plus 2% a year. The bill feels heavy because the tax rate climbed or a new bond passed, not because the value is wrong.

On recently purchased or recently improved property, overassessment is possible. The assessor has to set the base year value at "full cash value" (fair market value) as of the transfer date or the completion of construction. ^[1] If the assessor used a number higher than what the property would have sold for on the open market that day, you have grounds to appeal.

There is also a Prop 8 temporary reduction. California Revenue and Taxation Code Section 51 lets and requires the assessor to temporarily lower assessed value when a property's current market value drops below its Prop 13 factored base year value. ^[10] This happened at scale during 2009 through 2012. The assessor is supposed to catch it on their own. Plenty do not. You can file for a Prop 8 review any time.

To sanity-check your value, pull recent sales of comparable homes (same size, condition, and neighborhood) from the assessor's roll or from Zillow or Redfin, dated near the day your base year value was set. If those comps sold for meaningfully less than your assessed value on that date, you have a real case.

The formal route is an Assessment Appeal. File with the county Assessment Appeals Board (or an Assessment Hearing Officer in smaller counties). The California State Board of Equalization puts out a guide called "Assessment Appeals" that spells out the process for all 58 counties. ^[2] Most counties run a July 2 through November 30 filing window for regular assessments. Miss it and you wait a year.

Want to file yourself and skip the contingency firm that takes 30% to 50% of your savings? TaxFightBack's DIY appeal kit walks you through picking comparables, drafting the petition, and presenting at the hearing. You keep 100% of whatever reduction you win.

How is California property tax different from other states?

Most states reappraise property on a schedule, often yearly or every two to four years, so assessed value tracks the market pretty closely. California does not. That one fact explains almost everything odd about property tax here.

Because assessed values freeze at purchase and creep up slowly, two identical homes on the same street can carry wildly different bills. The California Legislative Analyst's Office, in its explainer on Proposition 13, found that assessed values for single-family homes in California average roughly 40% to 50% below market value, with the widest gaps on long-held homes in high-appreciation areas like the Bay Area. ^[11]

For a new buyer, the effective rate on what you actually paid is basically the full 1.1% to 1.6%. For a 30-year owner, the effective rate on today's market value might be 0.3% to 0.4%. Nobody is getting robbed. They just bought at different times.

Compare the field. New Jersey's average effective rate runs above 2% of market value a year. Cook County, Illinois hovers near 2.2%. Texas, with no income tax and heavy property tax, averages above 1.6% of market value. ^[9] California's Prop 13 does produce lower lifetime property tax for people who stay put, and it front-loads more cost onto whoever buys next.

For how the tax works nationally, the property tax taxation overview page covers the broader system.

What are the property tax payment deadlines in California?

California's property tax fiscal year runs July 1 through June 30, billed in two installments. These dates come from California Revenue and Taxation Code Sections 2605 and 2618. ^[7]

Installment	Period covered	Due date	Delinquent if paid after
First installment (50% of bill)	July 1 - Dec 31	November 1	December 10
Second installment (50% of bill)	January 1 - June 30	February 1	April 10

Miss December 10 and a 10% penalty hits right away. Miss April 10 and you get a 10% penalty plus a $10 cost fee. If the full year's tax is still unpaid at June 30, the property goes tax-defaulted and a 1.5% per month redemption penalty starts stacking up. ^[7]

Counties take payment online, by mail, or in person. Many now offer monthly ACH installment plans to smooth the year out, though you have to enroll on purpose. Check your county tax collector's website for the sign-up.

Paying through a mortgage escrow account? The servicer is supposed to handle these dates, but they slip up. Confirm your escrow is funded correctly after any refinance or servicer transfer.

How do I calculate property tax for a newly purchased California home?

The first year runs a little more complicated because the tax gets prorated between the seller's old assessed value and your new base year value.

Here is the sequence. The deed records, the county assessor gets notice of the transfer, and the assessor sets a new base year value equal to your purchase price. For the slice of the tax year before closing, the tax reflects the seller's old value. For the slice after closing, it reflects yours.

So you may get a "supplemental tax bill" on top of the regular annual bill. The supplemental bill captures the difference between the prior assessed value and your new base year value, prorated for the months left in the tax year (and sometimes rolling into the next year if the transfer landed in the first half of the fiscal year). ^[12]

Supplemental bills catch a lot of new owners off guard because they assumed they only owed the escrow estimate. Budget for it. If you paid far more than the prior owner's assessed value, the supplemental bill can be steep.

Quick estimate: (Your Purchase Price − Prior Assessed Value) × Tax Rate × (Months Remaining in Tax Year / 12). Pay $900,000 on a home the prior owner had assessed at $300,000, and the supplemental difference is $600,000. At 1.15%, that is $6,900 for a full year, prorated for however many months are left.

For LA County property tax or Santa Clara property tax specifics, those county guides cover local bond rates and supplemental billing timelines.

Can my property tax assessment be appealed and what could I save?

Yes. Every California property owner can appeal the assessed value to their county's Assessment Appeals Board under California Revenue and Taxation Code Section 1603. ^[10]

The window for regular assessments is July 2 through November 30 in most counties. A handful run different windows, so confirm with your local board. Filing is free or costs a nominal fee, often $30 to $60 depending on the county.

The burden of proof depends on what you are challenging. Appealing a base year value set at purchase? You have to show the assessor's value ran higher than the property's actual market value on the transfer date. Comparables, meaning similar homes sold within a reasonable time around that date, are the standard evidence.

Appealing under Prop 8 (current market below your factored base)? You need current market evidence instead.

The average dollar reduction on successful residential appeals is not tracked precisely at the state level. The California Board of Equalization's annual reporting shows that in recent years roughly 30% to 40% of residential appeals produce some reduction, though the BOE notes the share swings widely by county. ^[2]

For an organized homeowner, a self-filed appeal is very doable. You do not need an attorney or a contingency firm. The TaxFightBack DIY appeal kit hands you the templates, the comparable-selection method, and a hearing-prep checklist to walk in with a clean case. Filing fees stay low, the timeline is knowable, and any reduction you win stays entirely yours.

For Bay Area appeal procedures, the San Mateo County property tax and Santa Clara property tax guides cover local Assessment Appeals Board rules.

Are there calculators or official tools I can use to estimate my California property tax?

Several real tools exist, and the good ones are county-run.

The California State Board of Equalization does not run a public parcel-level calculator, but it publishes county-level tax rate data so you can find your specific TRA's rate. ^[2]

Most county assessor and tax collector websites have a property lookup. Type in an address and you see current assessed value, exemptions applied, and total tax owed. The Los Angeles County Assessor, the Santa Clara County Assessor (sccassessor.org), and the San Mateo County Assessor all run free public search tools. ^[5]

To estimate future tax on a home you are considering, the formula is: Purchase Price × Your TRA's Total Tax Rate. Get the TRA rate from the county assessor for any address on your list. Then add a rough Mello-Roos figure (the listing agent or seller disclosure should supply it for new subdivisions).

For paying online once you know the number, the online tax payment for property guide covers how California counties handle digital payments.

One thing calculators miss: bonds voters approve after you check the rate will push it up. Rates are not frozen. A school bond that passes in November shows up on the next tax roll.

Frequently asked questions

How do I calculate my property tax in California if I just bought a home?

Multiply your purchase price by the total tax rate for your parcel's tax rate area. That rate is at least 1% (the Prop 13 base) plus local voter-approved bond levies, usually landing between 1.05% and 1.6% total. Also budget for a supplemental tax bill covering the difference between the prior owner's assessed value and your new base year value, prorated for the remaining months in the tax year.

What is the 1% property tax rule in California?

Proposition 13, passed in 1978, limits the general property tax levy to 1% of assessed value. It is a constitutional provision in Article XIII A. It does not cap your total bill, because counties can add voter-approved debt levies on top of the 1%. But no general-purpose levy can exceed the 1% base without a new constitutional amendment.

How much can my California property tax assessment increase each year?

Under Proposition 13, the annual increase in assessed value is capped at 2% or the California CPI change, whichever is lower. The California State Board of Equalization publishes this inflation factor each year. For 2024-25 it was 2.0%. For a property that sold recently, the base year resets to the sale price regardless of the 2% cap.

What is a supplemental property tax bill in California?

A supplemental bill reflects the extra tax owed after a change of ownership or new construction raises your assessed value mid-year. It covers the difference between the prior assessed value and the new base year value, prorated for the portion of the fiscal year left after the change. New buyers often get one or two supplemental bills in the first year and should budget for them apart from the regular annual bill.

How do I find my California property's assessed value?

Your annual property tax bill from the county tax collector lists it. You can also search your county assessor's public portal by address or assessor's parcel number (APN). The APN is printed on your deed and your tax bill. Every California county assessor keeps a searchable online database, most of them free with no login.

What exemptions can reduce my California property tax bill?

The most common is the Homeowners' Exemption ($7,000 off assessed value for owner-occupied primary residences), worth about $70 to $77 a year. Disabled veterans can get $100,000 or more off assessed value. Proposition 19 lets homeowners 55 and older transfer their base year value to a replacement home anywhere in California. File exemption claims with your county assessor.

What are the property tax payment due dates in California?

The first installment (July 1 through December 31) is due November 1 and delinquent after December 10. The second installment (January 1 through June 30) is due February 1 and delinquent after April 10. A 10% penalty applies immediately after each delinquency date. These dates are the same across all 58 California counties under Revenue and Taxation Code Sections 2605 and 2618.

How do I appeal my California property tax assessment?

File an Application for Changed Assessment with your county Assessment Appeals Board. The standard window is July 2 through November 30 each year for regular assessments. Filing fees run roughly $30 to $60 depending on county. You have to show the assessor's value exceeds the property's market value. Comparable sales are the primary evidence. No attorney is required. Homeowners file successfully on their own all the time.

What is a Mello-Roos tax and how does it affect my California property tax?

Mello-Roos is a special tax levied by a Community Facilities District (CFD), authorized under the Mello-Roos Community Facilities Act of 1982. It funds infrastructure and services in newer developments. It shows up as a line item on your tax bill and can add several hundred to several thousand dollars a year. Unlike the 1% levy, it is not based on assessed value but on a fixed charge or formula. California sellers must disclose CFD status.

How does California property tax compare to other states?

California's effective rate on market value averages around 0.75%, per the Lincoln Institute of Land Policy's 50-State comparison, lower than most states because Prop 13 keeps assessed values below market on long-held homes. New Jersey averages above 2%, Cook County Illinois above 2%, and Texas above 1.6%. New buyers in California pay closer to the full 1.1% to 1.5% statutory rate on what they paid.

What happens if I miss a California property tax payment?

A 10% penalty is added right after December 10 for the first installment and after April 10 for the second. If the property is still tax-defaulted after June 30, a 1.5% per month redemption penalty starts and the county records a tax default. After five years of default, the county can start a tax sale. Contact your county tax collector immediately if you miss a deadline; some counties cancel penalties for first-time errors.

Does Proposition 19 change how inherited property is taxed in California?

Yes, a lot. Since February 16, 2021, a child inheriting a parent's property can only keep the parent's low base year value if the child moves in as their primary residence. Even then the exclusion is capped: if the home's current market value exceeds the parent's assessed value by more than $1,000,000, the excess is taxed at market value. Non-primary-residence inherited property is reassessed to full market value at transfer.

How can I calculate property tax for a commercial property in California?

The same Prop 13 formula applies: assessed value (set at purchase or last transfer) times the total tax rate for the property's tax rate area. Proposition 15 (the "split-roll" measure) was on the 2020 ballot and would have reassessed commercial property to market value regularly, but California voters rejected it. Commercial property in California still keeps Prop 13 protection.

What is a Prop 8 reduction and can I request one?

California Revenue and Taxation Code Section 51 requires assessors to enroll the lower of a property's Prop 13 factored base year value or its current market value. If your home's market value has fallen below its assessed value (common in downturns), you can file a Prop 8 review request with your county assessor. There is no formal deadline for this type of request, unlike a standard assessment appeal.

Sources

1. California State Board of Equalization, Proposition 13 Overview: Proposition 13 (Article XIII A of the California Constitution) caps the general levy at 1% of assessed value and limits annual assessment increases to 2% or CPI, whichever is lower, with reassessment at change of ownership or new construction.
2. California State Board of Equalization, Property Tax Publications: BOE publishes annual inflation factors, county tax rate area data, and assessment appeals guidance for all 58 California counties; 2024-25 inflation factor was set at 2.00%.
3. California State Board of Equalization, Proposition 19 Information: Proposition 19 (effective February 16, 2021 for parent-child transfers; April 1, 2021 for base year value transfers) changed inherited property reassessment rules and expanded the base year value transfer for qualifying seniors, disabled persons, and disaster victims.
4. Santa Clara County Assessor's Office: Santa Clara County Assessor provides online property lookup showing assessed value, exemptions, and tax rate area for all parcels in the county.
5. California State Board of Equalization, Homeowners and Veterans Exemptions: The California Homeowners' Exemption reduces assessed value by $7,000 for owner-occupied primary residences; the Disabled Veterans' Exemption provides $100,000 to $150,000 in assessed value reduction for qualifying veterans.
6. California Revenue and Taxation Code Sections 2605 and 2618: First installment of property tax is due November 1 and delinquent after December 10; second installment is due February 1 and delinquent after April 10, with a 10% penalty on delinquent amounts.
7. California Civil Code Section 1102.6b: Sellers of residential property in a Mello-Roos Community Facilities District must disclose that status to buyers under California Civil Code Section 1102.6b.
8. Lincoln Institute of Land Policy, 50-State Property Tax Comparison Study: California's average effective property tax rate on residential property was approximately 0.75% of market value; New Jersey exceeds 2%, Illinois Cook County exceeds 2%, and Texas averages above 1.6% of market value.
9. California Revenue and Taxation Code Sections 51 and 1603: Section 51 requires the assessor to enroll the lower of factored base year value or current market value (Prop 8 review); Section 1603 grants every property owner the right to appeal assessed value to the county Assessment Appeals Board.
10. California Legislative Analyst's Office, Understanding Proposition 13: Assessed values for single-family homes in California average roughly 40-50% below current market values, with the largest gaps in high-appreciation Bay Area markets where long-held properties are concentrated.
11. California State Board of Equalization, Supplemental Assessments Guide: A supplemental assessment is issued after a change in ownership or new construction to capture the difference between the prior enrolled value and the new base year value, prorated for the fiscal year months remaining after the triggering event.