How to use the property tax calculator
- Enter your home's market value.
- Enter the assessment ratio — the share of market value the assessor taxes (100 percent in many places, less in others).
- Subtract any exemptions (homestead, senior, veteran).
- Enter the local tax rate as a percent of assessed value.
- Read the annual and monthly tax and the effective rate on the full price.
Worked example
A $400,000 home assessed at 100% with a $25,000 exemption and a 1.1% rate owes tax on $375,000, giving an annual bill of $4,125 (about $344 a month) — an effective rate of 1.03% on the market value.
Where the number comes from
Assessed = Market value x Assessment ratio
Taxable = Assessed - Exemptions
Annual tax = Taxable x Rate
The assessment ratio is the part that surprises buyers. In some states the assessor values a home at a fraction of what it would sell for, which lowers the bill even though the rate looks high. Exemptions work the same way — they shrink the taxable base before the rate is applied. Always check your assessment notice: if the assessed value is wrong, your bill is wrong too.