The basic calculation
Taxable value × rate ÷ 100
Calculate each taxing unit separately, then add the applicable levies.
Austin residents may see the City, county, school district, community college, health district, and special districts on one statement. The exact set depends on the parcel.
Three values that are not interchangeable
Market value
The appraisal district's estimate of market value as of January 1.
Appraised value
The value after an applicable appraisal limitation, such as the qualifying homestead cap.
Taxable value
The unit-specific value after exemptions. It can differ across units.
2026 Texas homestead rules
- Mandatory school-district general homestead exemption: $140,000.
- Additional school exemption for a qualifying owner age 65 or older or disabled: $60,000.
- Local taxing units may offer different additional exemptions.
- A continuing qualifying homestead's appraised value generally cannot rise more than 10% plus new improvements, and cannot exceed market value.
The 10% rule is not a tax-bill cap. Rates, exemptions, new improvements, and the mix of taxing units can change independently.
Use official parcel data
Start with the current appraisal notice. Then use the official truth-in-taxation database or tax statement to identify each taxing unit, its taxable value, and its adopted rate. A scenario calculator remains an estimate until the rates and roll are final.