What this calculator does
The homestead exemption is the biggest property tax break most Houston homeowners get, and it is free to claim with Harris Central Appraisal District (HCAD). This calculator compares your yearly tax with and without it for every taxing unit on a typical Houston ISD bill. A Houston home in Houston ISD is taxed by several units — the school district, City of Houston, Harris County, Harris Health, the Flood Control District, the Port of Houston and the Department of Education — for a combined rate of about $2.03 per $100 of value in 2025 before exemptions. The school homestead exemption rose to $140,000 after voters approved it in November 2025.
How to use it
- Enter the appraised value from your notice.
- Tick the box if an owner is 65 or older or disabled.
- Read the savings by taxing unit.
The formula
For each taxing unit, tax = (value − exemption) ÷ 100 × rate. The school district exempts $140,000 (plus $60,000 more for 65+ or disabled). The other units on the bill take a percentage off. Savings = tax without homestead − tax with homestead.
Worked example
Using the default inputs shown in the calculator above:
| Taxing unit | Savings per year |
|---|---|
| Houston ISD — exemption $140,000 | $1,230 |
| City of Houston — exemption $66,000 | $343 |
| Harris County — exemption $66,000 | $254 |
| Harris Health — exemption $66,000 | $124 |
| Harris County Flood Control District — exemption $66,000 | $33 |
| Port of Houston Authority — exemption $66,000 | $4 |
| Harris County Dept. of Education — exemption $66,000 | $3 |
| Total yearly savings | $1,990 |
Yearly savings from the homestead exemption: $1,990. Tax falls from $6,702 to $4,711 a year.
Most of the saving comes from the school district, because its $140,000 exemption removes a large, fixed slice of value at the highest rate on the bill. The other units take a percentage off instead, so their savings grow with your home's value.
How the homestead works in Houston
You qualify if you own the home and live in it as your principal residence on January 1. Apply with Harris Central Appraisal District (HCAD) — online or by mail — by April 30, though late applications are accepted for up to two years. Once granted, it also caps the yearly increase in your taxable value at 10%, which can matter more than the exemption itself in a hot market. Owners 65 and older get a school tax ceiling that freezes the school tax amount.
Common mistakes and tips
- Paying a company to file a homestead application — it is free with the appraisal district.
- Assuming it transfers automatically when you buy — new owners must apply.
- Forgetting to reapply after moving within the county.
- Not checking the over-65 exemption once an owner turns 65.
Frequently asked questions
How much does the homestead exemption save in Houston?
On a $330,000 home in Houston ISD, this calculator estimates the yearly saving shown above — most of it from the $140,000 school exemption.
When is the deadline?
April 30 for the current year, but Harris Central Appraisal District (HCAD) accepts late applications up to two years after the deadline.
What is the 10% homestead cap?
For a homestead, the appraised value used for tax can rise no more than 10% a year (plus new improvements), even if the market value rises faster.
Did the school exemption change in 2025?
Yes. Texas voters approved raising it from $100,000 to $140,000 in November 2025, and to $200,000 for 65+ or disabled owners.
Sources
Disclaimer
This calculator provides estimates for educational purposes only and is not financial, tax, legal, real estate, or insurance advice. Consult a licensed professional before making decisions.