How property tax is calculated
Most property taxes follow three steps. Assessed value = market value × assessment ratio. Taxable value = assessed value − exemptions. Tax = taxable value × rate.
The rate can be written three ways. A percent rate is divided by 100. A millage rate is in mills, where one mill is 1 per 1,000 of taxable value, so divide by 1,000. A rate per 100 of value is divided by 100. A 20-mill rate, a 2.00 per 100 rate and a 2% rate are all the same.
Worked examples
A home worth 350,000, assessed at 100% of value with no exemptions and a 1.2% rate, owes 350,000 × 0.012 = 4,200 a year, or 350 a month if set aside monthly.
Where property is assessed at 40% of market value, a 200,000 home has an assessed value of 80,000. After a 25,000 homestead exemption the taxable value is 55,000, and at 30 mills the tax is 55,000 × 30 ÷ 1,000 = 1,650 a year.
Where to find your numbers
This calculator holds no local rates or assessment rules; you supply them. Your tax bill or the assessor's website usually shows the assessed value, the exemptions applied and the combined rate from the county, city, school district and any special districts.
The result is an estimate. Assessment caps, circuit-breaker credits, special assessments, reassessment after a sale and installment schedules vary by jurisdiction and are not modeled.