Property Tax Calculator

How This Calculator Works

Property tax is calculated by applying your local tax rate to your home’s assessed value — not directly to its market value. Enter your home’s market value, the assessment ratio your local taxing authority uses, and the effective tax rate, and this calculator estimates your annual (and monthly) property tax bill.

In many places, assessed value simply equals market value (a 100% assessment ratio). In others, the local government assesses homes at only a fraction of market value — which is exactly what the Assessment Ratio field accounts for, so the calculation still works correctly either way.

The Formula

$$\text{Annual Property Tax} = \vA{\text{Market Value}} \times \vB{\text{Assessment Ratio}} \times \vC{\text{Tax Rate}}$$

The U.S. Census Bureau’s own commonly-cited national average effective property tax rate is about 1.1% — a useful starting point, not a substitute for checking your own county assessor’s actual rate, since real rates vary enormously by state and county.

Worked Example

A $400,000 home, with a 100% assessment ratio and a 1.1% effective tax rate:

1. Assessed value: $400{,}000 \times 1.00 = 400{,}000$.
2. Annual property tax: $400{,}000 \times 0.011 = \$4{,}400$ (about $366.67/month).

Common Mistakes

• Applying the tax rate directly to market value everywhere. Some jurisdictions do exactly that (a 100% assessment ratio), but others assess at a fraction of market value — always confirm your own local convention rather than assuming.
• Treating the national average rate as your own rate. Property tax rates vary by a factor of 8 or more between the highest- and lowest-taxed states — this default is a starting point for exploring the calculator, not a stand-in for your actual bill.
• Confusing a “mill rate” with a plain percentage. Many local governments quote rates in mills (dollars per $1,000 of assessed value) rather than percent — see the FAQ for the quick conversion.