Property Tax Calculator
Calculate annual property tax by multiplying the home value by the mill rate and dividing by 1,000 — the standard formula used by US municipalities and many other property-tax jurisdictions. Use it to estimate the tax bill on a home you're buying or to project future taxes after a reassessment.
Last updated: May 2026
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About this calculator
The formula is: property tax = (home value × mill rate) ÷ 1,000. The mill rate (also called millage) is the tax rate expressed in mills, where one mill equals one-tenth of a percent (0.1%) or $1 of tax per $1,000 of property value. A mill rate of 20 means $20 of tax per $1,000 of value, or 2.0%. Some jurisdictions express the rate as a percentage directly instead of in mills; in that case multiply value × rate ÷ 100. The home value in the formula should be the assessed value used by the taxing authority, which is often different from the market value: many jurisdictions assess at 80–100% of market value, some use formulas that lag the market (Proposition 13 in California caps annual assessment increases at 2%), and homestead exemptions reduce the assessed value by a flat amount for owner-occupied primary residences. Edge cases: zero home value or zero mill rate produces zero tax; very high mill rates (over 100 mills, or 10%+) are unusual but exist in a few municipalities with depressed property values. Property tax rates vary enormously: nationally, the average effective property tax in the US is about 1.0%, but state-level effective rates range from 0.3% (Hawaii) to over 2.0% (New Jersey, Illinois). The tax funds local services — schools, fire, police, roads, libraries — and is the primary funding source for public education in most states, which is why high-tax states often have well-funded schools and the inverse is also generally true.
How to use
Example 1 — Standard mid-tax state. Home assessed at $385,000 with a local mill rate of 18 (1.8% effective rate). Enter 385000 for Home Value and 18 for Mill Rate. Result: $6,930 annual property tax. Verify: 385000 × 18 / 1000 = $6,930. ✓ Roughly $578 per month, typically escrowed into the mortgage payment. At a 1.8% effective rate, this is close to the national median. Example 2 — High-tax New Jersey suburb. Home assessed at $620,000 with a mill rate of 27 (2.7% effective rate). Enter 620000 and 27. Result: $16,740 annual property tax. Verify: 620000 × 27 / 1000 = $16,740. ✓ Roughly $1,395 per month — a meaningful portion of any monthly housing budget and worth checking carefully before buying in a high-tax jurisdiction. The high rate typically funds top-rated public schools, which is part of why the property values stay strong despite the tax burden.
Frequently asked questions
What is a mill rate and how does it differ from a percentage?
A mill is one-tenth of one percent, or $1 of tax per $1,000 of property value. So a mill rate of 20 equals 2.0%, and a mill rate of 12.5 equals 1.25%. Many municipalities express property tax rates in mills rather than percentages because the assessed values are in dollars and mills produce cleaner arithmetic — a home assessed at $300,000 with a 15 mill rate produces 300 × 15 = $4,500 of tax via simple multiplication. The percentage and mill expressions are mathematically identical: 15 mills = 1.5%. Some jurisdictions use a "tax rate per $100" of value instead — a rate of 1.5 per $100 also equals 1.5%. Always confirm the unit the rate is expressed in before plugging numbers into a calculator.
What is the difference between assessed value and market value?
Market value is what the property would sell for in an open transaction today; assessed value is the figure the taxing authority uses for tax calculations. The relationship varies by state. Many states assess at 100% of market value (or close to it), reassessing every 1–3 years. Some assess at a fraction of market value (Connecticut at 70%, Michigan at 50%) but make up the gap with higher mill rates so the effective tax rate is comparable. California's Proposition 13 caps annual assessment increases at 2% per year for properties not recently sold, so long-held homes have assessed values far below market — a $1.5M house bought in 1985 might have an assessed value under $300,000 and pay tax accordingly. When using this calculator, ALWAYS use the assessed value (which you can find on your property-tax bill or county assessor's website), not the Zillow estimate of market value, or you'll overstate the tax bill.
How do exemptions and tax breaks work?
Most jurisdictions offer exemptions that reduce assessed value before applying the mill rate. The most common is the homestead exemption, which reduces the assessed value of an owner-occupied primary residence by a flat amount (often $25,000–$75,000 depending on jurisdiction). Senior exemptions, veteran exemptions, and disability exemptions provide additional reductions for qualifying residents. Some jurisdictions also offer "circuit-breaker" programs that cap property tax as a percentage of household income for low-income residents. These exemptions can substantially reduce the tax bill — in some Florida counties, the homestead exemption + the Save Our Homes assessment cap can reduce property tax by 50%+ for long-held primary residences. Always file for any exemptions you qualify for; some are automatic but most require an application and yearly verification.
What are the most common mistakes people make with property tax estimation?
The biggest is using market value (from Zillow or recent sale comps) instead of assessed value — for properties in low-cap states (California, Florida with homestead exemption), the assessed value can be far below market and the real tax bill is correspondingly lower than market value implies. The second is forgetting that mill rates change annually as municipalities set budgets — last year's mill rate is a guide, not a guarantee. The third is missing special assessments (school bonds, infrastructure projects, fire-district levies) that add to the base mill rate on a temporary or permanent basis. The fourth is not applying for available exemptions; the homestead exemption alone can save $500–$2,000+ per year for owner-occupants. The fifth is forgetting that property tax is deductible on federal taxes only up to the $10,000 SALT cap (combined with state income and sales taxes) — so high-property-tax states no longer get full federal deduction relief. Finally, people often forget that property tax rates can shift dramatically across municipal lines: two houses three blocks apart in different towns can pay $5,000 vs $15,000 in tax for similar values.
When should I not use this calculator?
Skip it for new construction without checking how the assessed value will be set after completion — the developer's estimate is often optimistic, and the first full assessment may push the bill significantly higher than initial estimates. It is the wrong tool for commercial property, agricultural property, or special-use property (forests, wetlands), all of which often have different rate schedules or use formulas not captured by this simple multiplication. Do not use it for jurisdictions that express tax as a fixed dollar amount per parcel (some rural districts) rather than a percentage of value. It also doesn't handle property-tax reassessment timing — buying a home triggers a reassessment in most jurisdictions, so the seller's old tax bill may significantly understate what you'll pay. For an accurate figure on a specific purchase, look up the property on the county assessor's website, find the current assessed value and any exemptions, and apply the current mill rate. And for tax appeals (claiming the assessment is too high), use a property-tax-appeal calculator that compares your assessment against comparable sales.