California Property Tax Estimator
Estimate your annual California property tax using Proposition 13’s base-year value, the 2% assessment cap, your county’s rate, and the Homeowner’s Exemption.
Your Property
Proposition 13 Base Year Value
This sets your Prop 13 base year – the year your property was last reassessed at full value.
The price you paid at purchase. If you’re not sure, your county assessor’s site lists your current assessed value.
Optional – enter this to see your personal Prop 13 savings box below, and to account for temporary Prop 8 reductions if the market ever fell below your Prop 13 value.
Exemptions
Your Estimate
Select your county, enter your purchase year and price, and click Estimate my property tax.
Prop 13 Base Year Value
Exemptions
Tax Calculation
This calculator estimates your standard California property taxes under Proposition 13. Homes located in Community Facilities Districts (CFDs) may also owe Mello-Roos taxes, which are separate from regular property taxes and can significantly increase your annual tax bill.
Learn about Mello-Roos Taxes →
Estimate only. This calculator applies California’s Proposition 13 rules – your purchase price as the base year value, capped at 2% annual growth – and a composite county tax rate approximating the 1% general levy plus typical voter-approved debt. Actual rates vary by tax rate area within a county, and this estimate does not include Mello-Roos, CFDs, parcel taxes, or other direct assessments. For your exact assessed value and tax rate area, contact your county assessor.
Why does my neighbor pay less property tax than I do?
Your property tax in California is based primarily on when you purchased your home – not its current market value. Two identical homes on the same street can have dramatically different tax bills if one owner purchased in 1995 and the other purchased in 2024.
Proposition 13 limits annual increases in assessed value to a maximum of 2% until the property changes ownership or undergoes new construction. The longer someone has owned their home, the further their assessed value falls behind current market value – and the lower their tax bill, relative to a recent buyer of the same house.
This isn’t a mistake or an unfair loophole – it’s exactly how Prop 13 was designed to work when California voters passed it in 1978, and it applies the same way to every homeowner in the state.
About This Estimate
- Why purchase year matters more than anything else. Under Proposition 13, your property is reassessed at full market value only when you buy it (or complete new construction). From that point, your assessed value – your “base year value” – can rise by no more than 2% a year, no matter how much the market climbs. That means two identical houses on the same street can carry very different tax bills depending on when their current owners bought in.
- Factored base year value. This calculator grows your purchase price by 2% for each year you’ve owned the home. In almost all years since 1978 the actual statutory factor has been at or very close to 2%, so this is a close approximation – but your county assessor’s number is the exact figure of record.
- Prop 8 decline-in-value. If a home’s market value drops below its Prop 13 factored value (as happened widely after 2008), the county temporarily assesses at the lower market value instead. This calculator applies that rule if you provide a current market value below your factored base year value. The reduction is temporary – the assessment can climb again once the market recovers, still capped at 2% per year.
- Homeowner’s Exemption. California offers a flat $7,000 reduction in assessed value for an owner-occupied primary residence. Unlike Florida’s homestead exemption, this amount is small and hasn’t been adjusted for inflation in decades – it barely moves the needle on a typical bill.
- County composite rate. Prop 13 limits the general tax levy to 1% of assessed value, but nearly every county adds voter-approved debt service for schools and infrastructure on top of that, typically bringing the total to somewhere between 1.04% and 1.18%. This calculator uses an approximate composite rate for each county; your exact rate depends on your specific tax rate area.
- What’s not included. Mello-Roos taxes and Community Facilities District charges are common in newer subdivisions and are billed as flat or formula-based parcel charges, not a percentage of value – so they can’t be estimated from assessed value alone. New construction, major remodels, and Proposition 19 base-year-value transfers (for owners 55+, disabled, or displaced by wildfire or disaster) also aren’t modeled in this version.