Your property tax is your home’s taxable value times your local tax rate. Taxable value is the assessed value (market value times the assessment ratio your area uses) minus any exemptions you have been granted. Every input comes from your local assessor and tax collector, so this calculator gives you the math, not the rates.
The formula
- Assessed value
- Market × ratio
- Ratio is 100% where property is assessed at full value
- Taxable value
- Assessed − exemptions
- Never below $0
- Annual tax
- Taxable × rate
- Rate as a decimal
- 1 mill
- $1 per $1,000
- = 0.1% = $0.10 per $100
How the calculation works
New York State’s tax department puts it simply: taxes owed equal your taxable assessment times the tax rate per thousand. A local government sets its rate by dividing the amount it needs to raise from property tax (the levy) by the total taxable assessed value in its area. In the state’s example, a $2,000,000 levy over $40,000,000 of taxable value gives a rate of $50 per $1,000, so a home with a $150,000 taxable assessment owes $7,500.
- Assessment ratio. Some places assess at full market value. Others assess at a fixed fraction. A low ratio is not a discount: the rate is set higher to collect the same levy.
- Exemptions. Homestead, senior, veteran and disability exemptions usually reduce assessed value by a dollar amount or a percentage. Enter the total dollar reduction shown on your notice.
- Rate units. Rates are quoted in mills ($ per $1,000), in percent, or in dollars per $100. The tool converts any of them to a decimal: mills ÷ 1,000, percent ÷ 100, or $ per $100 ÷ 100.
- Combined rate. Your bill usually stacks several taxing units: county, city or town, school district and special districts. Add their rates before entering them.
Worked example
Say your home’s market value is $400,000, your town assesses at 50% of market value, you have a $10,000 homestead exemption, and the combined rate is 30 mills. These numbers are made up for the example; use your own.
| Step | Math | Result |
|---|---|---|
| Assessed value | $400,000 × 50% | $200,000 |
| Taxable value | $200,000 − $10,000 | $190,000 |
| Annual tax | $190,000 × 0.030 | $5,700 |
| Monthly (escrow) | $5,700 ÷ 12 | $475 |
| Effective rate | $5,700 ÷ $400,000 | 1.43% |
The effective rate (tax divided by market value) is the number to compare across towns, because headline rates and ratios differ so much. If the assessment rose 10% with the same rate and exemption, taxable value would be $210,000 and the tax $6,300, or $600 more. The table in the calculator shows these what-ifs for your numbers.
Reading your bill and appealing
Check three things on your assessment notice: the market value the assessor used, the assessed value, and every exemption you expected. If the market value is higher than recent sales of similar homes, or an exemption is missing, contact the assessor. Most places have a short yearly window to challenge an assessment, and the deadline is printed on the notice. Missing it usually means waiting a year.
Next steps
- In New York City, use the NYC property tax estimator, which handles tax classes and assessment caps, and read NYC property tax explained.
- Add the tax to your full payment with the mortgage calculator or see what you can afford with the home affordability calculator.