Property Tax Estimator

Property tax is an annual tax levied by local governments (counties, municipalities, school districts) based on the assessed value of real estate you own. It is the primary funding source for local public schools, fire departments, and infrastructure.

Core formula: Annual Property Tax = Assessed Value × Mill Rate ÷ 1,000

Alternatively expressed as: Annual Property Tax = Assessed Value × Effective Tax Rate

What each variable means:

• Assessed Value: the value assigned to your property by the local tax assessor. This is often not the same as market value. Many jurisdictions assess at 70–100% of market value; some assess at a fixed fraction (e.g., 40%).
• Mill Rate: the tax rate expressed in mills. One mill = $1 of tax per $1,000 of assessed value. A mill rate of 20 = 2.0% effective tax rate.
• Effective Tax Rate: the simpler decimal form: (Annual Tax ÷ Market Value × 100). Ranges from about 0.3% (Hawaii) to 2.5%+ (New Jersey, Illinois).

Assessment ratio: Assessed Value = Market Value × Assessment Ratio

Many counties do NOT assess at 100% of market value. Always check your local assessment ratio before estimating taxes.

Common exemptions that reduce assessed value:

• Homestead exemption: for primary residence owners (reduces taxable value by $15,000–$50,000 depending on state)
• Senior exemption: additional reduction for homeowners 65+
• Veteran exemption: for qualified military veterans
• Disability exemption: for disabled homeowners

Mills or percent, and how to convert. A mill is $1 per $1,000 of assessed value. Divide mills by 10 to get the percentage: 22.5 mills is 2.25%, 14 mills is 1.4%. The dropdown above takes either, so use whatever your tax bill prints rather than converting in your head.

Worked example: A $380,000 home in a county that assesses at 80%, charges 22.5 mills, and allows a $25,000 homestead exemption.

• Assessed value: $380,000 × 0.80 = $304,000
• Taxable value: $304,000 − $25,000 = $279,000
• Annual tax: $279,000 × 22.5 ÷ 1,000 = $6,277.50
• Monthly escrow: $523.13

Notice that the exemption saved $562.50 a year, and that it is worth exactly the same to a $200,000 house as to a $2,000,000 one. A flat exemption is proportionally far more valuable at the bottom of the market, which is the point of it.

Effective rate against nominal rate. Your effective rate is the tax divided by what the house is actually worth, and it is the only figure that compares across state lines. A county quoting 22.5 mills on an 80% assessment has an effective rate of 1.8%, not 2.25%, and a county quoting 4% on a 25% assessment charges the same 1% as one quoting 1% on a full assessment. The nominal rate on its own tells you nothing.

Average effective rates by state:

• Lowest: Hawaii 0.32%, Alabama 0.41%, Colorado 0.51%, Nevada 0.55%
• National average: about 1.10%
• Highest: Texas 1.63%, Illinois 2.08%, New Jersey 2.49%

Two things that will change your bill without the rate moving. A revaluation raises the assessment while the rate stays put, which is how most towns raise revenue quietly. And a homestead exemption usually has to be applied for, once, and plenty of owners never do. Both are worth checking on your assessment notice.