California Property Tax Calculator
What Buyers Pay Under Prop 13
Estimate your annual tax, supplemental bill, and Prop 19 savings — with real Santa Clara County city rates, Mello Roos flags, and payment due dates.
YOUR SCENARIO
Estimate annual property tax
[VERIFY] Effective rates include base 1% + voter-approved bonds. Source: sccassessor.org
ANNUAL ESTIMATE
1.25% rateEstimate only. Actual tax varies by parcel. Look up the specific address at sccassessor.org.
Review My Numbers with XavierSANTA CLARA COUNTY
Property Tax Payment Due Dates
[VERIFY from sccgov.org — Tax Collector's office
ⓘ If you have an impound/escrow account, your lender collects 1/12 of annual taxes each month and pays both installments automatically — you don't need to track these deadlines yourself. Most purchase loans in Santa Clara County include impound accounts.
SANTA CLARA COUNTY
City-by-City Property Tax Rates
[VERIFY] Effective rates = base 1% + voter-approved bonds. Source: sccassessor.org. Annual figures based on assessed value = purchase price (Prop 13).
| City | Base Rate | Bond Add-ons | Effective Rate | Tax on $1M | Tax on $1.5M | Tax on $2M |
|---|---|---|---|---|---|---|
| San Jose | 1.00% | 0.25% | 1.25% | $12,500 | $18,750 | $25,000 |
| Sunnyvale | 1.00% | 0.20% | 1.20% | $12,000 | $18,000 | $24,000 |
| Santa Clara | 1.00% | 0.23% | 1.23% | $12,300 | $18,450 | $24,600 |
| Cupertino | 1.00% | 0.22% | 1.22% | $12,200 | $18,300 | $24,400 |
| Mountain View | 1.00% | 0.18% | 1.18% | $11,800 | $17,700 | $23,600 |
| Palo Alto | 1.00% | 0.17% | 1.17% | $11,700 | $17,550 | $23,400 |
| Los Altos | 1.00% | 0.17% | 1.17% | $11,700 | $17,550 | $23,400 |
| Los Altos Hills | 1.00% | 0.15% | 1.15% | $11,500 | $17,250 | $23,000 |
| Saratoga | 1.00% | 0.15% | 1.15% | $11,500 | $17,250 | $23,000 |
| Monte Sereno | 1.00% | 0.15% | 1.15% | $11,500 | $17,250 | $23,000 |
| Campbell | 1.00% | 0.21% | 1.21% | $12,100 | $18,150 | $24,200 |
| Los Gatos | 1.00% | 0.18% | 1.18% | $11,800 | $17,700 | $23,600 |
| Milpitas | 1.00% | 0.27% | 1.27% | $12,700 | $19,050 | $25,400 |
| Morgan Hill | 1.00% | 0.30% | 1.30% | $13,000 | $19,500 | $26,000 |
| Gilroy | 1.00% | 0.37% | 1.37% | $13,700 | $20,550 | $27,400 |
| Menlo Park | 1.00% | 0.15% | 1.15% | $11,500 | $17,250 | $23,000 |
| Unincorporated SCC | 1.00% | 0.20% | 1.20% | $12,000 | $18,000 | $24,000 |
[VERIFY] All figures require verification at sccassessor.org — bond measures change at each election. Mello Roos (if applicable) is separate and not included in these rates. Data current as of 2026 Q1 — confirm before making an offer.
How Prop 13 Sets Your Property Tax in California
California's Proposition 13, passed in 1978, fundamentally changed how property taxes work in the state. Under Prop 13, your property tax is based on your purchase price — not the current market value. Once you buy, your assessed value can only increase a maximum of 2% per year, regardless of what the market does.
This is enormously valuable over time. A homeowner who bought in Palo Alto in 2005 for $800,000 might have a current assessed value of just $1.1M — even though the home is now worth $3.5M+ — paying taxes on the Prop 13 basis rather than market value.
For buyers, the flip side is that your purchase price becomes your new assessed value. Every time a home sells, the county resets the tax base. In a high-cost market like Santa Clara County, this means your annual property tax is a meaningful budget item.
Understanding the Effective Tax Rate (It's More Than 1%)
California's base property tax rate is 1%. But that's not what you pay. Every city in Santa Clara County layered voter-approved bonds on top — for schools, community colleges, parks, and infrastructure. These bonds are legal under Prop 13 because they require a separate voter vote, not just a legislative action.
The result: effective rates in Santa Clara County range from roughly 1.15% to 1.37% depending on city. San Jose (1.25%) carries more bond measures than Saratoga (1.15%). Gilroy (1.37%) reflects significant infrastructure investment in a developing market. These are averages — your specific parcel may differ due to local CFD or special assessment districts.
Use the calculator above to estimate your annual tax by city. Always verify the specific parcel at sccassessor.org.
What Is a Supplemental Property Tax Bill?
When you buy a home in California, the county assessor issues a supplemental assessment — the difference between the prior owner's assessed value and your purchase price. You owe tax on this difference, prorated for the remaining months in the fiscal year (July 1 – June 30).
Example: You close in October on a $1.2M home where the prior assessed value was $600K. The $600K difference, taxed at San Jose's 1.25% rate, generates $7,500 in annual tax. With 9 months remaining in the fiscal year, your supplemental bill is approximately $5,625.
Important: Santa Clara County may send two supplemental bills — one covering the remainder of the current fiscal year, and a second for the following full year (if your close falls in the second half of the fiscal year). Expect these 6–18 months after close.
If you have an impound account, talk to your lender about how supplemental bills are handled — they are not automatically paid from your standard impound reserves.
Prop 19: The 55+ Property Tax Transfer
California Proposition 19 (effective February 16, 2021) allows homeowners 55 or older to sell their current home and transfer their Prop 13 assessed value to a new primary residence — anywhere in California, up to three times in their lifetime.
The transfer formula works like this: If your new home costs less than or equal to the fair market value of the home you're selling, your new assessed value equals your current Prop 13 basis. If the new home costs more, your new assessed value is your current basis plus the price difference.
Example: You have a Prop 13 basis of $400K on a home now worth $1.8M. You buy a new home for $1.5M in San Jose. The transfer works — your new assessed value is $400K, not $1.5M. Annual savings: ($1.5M - $400K) × 1.25% = $13,750/year, or $137,500 over 10 years.
Prop 19 is one of the most powerful financial tools available to 55+ homeowners in California. If you're considering a move, explore our Silicon Valley 55+ communities guide and talk to Xavier about timing your sale and purchase to maximize the tax benefit.
Mello Roos: The Hidden Property Tax in New Construction
Mello Roos taxes (officially, Community Facilities District levies) fund public infrastructure in newer developments — schools, fire stations, roads, parks. They're most common in developments built after the 1980s and are a significant budget item that most online calculators completely ignore.
In Santa Clara County, Mello Roos is most prevalent in newer developments in south San Jose (Coyote Valley area), newer subdivisions in Milpitas, Morgan Hill, and Gilroy. Annual assessments typically range from $2,000 to $8,000 per year, adding $167–$667 to your monthly payment — on top of the base property tax.
Unlike Prop 13 taxes, Mello Roos assessments can increase on a fixed schedule and don't follow the 2% annual cap. The only reliable way to know if a specific property has Mello Roos is to check the Natural Hazard Disclosure (NHD) report — required in every California residential transaction — or look up the parcel at sccassessor.org.
If you're considering a new construction home in Santa Clara County, ask to see the specific Mello Roos assessment before making an offer. Xavier can pull this data for any property you're evaluating.
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