The Math
How Your Property Tax Gets Figured
It looks complicated, but it comes down to a simple formula and two numbers. Here's how it works.
Bottom line: your tax is your home's assessed value multiplied by the millage rate. Once you know those two numbers, you can estimate the bill on any home — including one you're thinking about buying.
The formula
Bottom line: two numbers, one multiplication.
That's the whole engine. The rest is just understanding what those two numbers mean and where they come from.
Assessed value and millage rate
Bottom line: one comes from the assessor, one from local governments.
- Assessed value: a percentage of your home's fair market value, set by the county assessor's office
- Millage rate: the tax rate, set each year by municipalities and school districts
Because the millage rate is reviewed annually, your bill can shift over time even if your home's value holds steady.
Estimating before you buy
Bottom line: you can ballpark taxes on a home before making an offer.
Use the relevant county's online tax calculator, or just ask your agent. Two things to remember: include the city millage if the home is inside Summerville town limits, and use the right assessment ratio — a primary residence and a rental aren't taxed the same. This pairs naturally with our step-by-step buying guide.
To estimate a home's taxes
- Find the assessed value (a share of market value)
- Look up the millage for that county and district
- Add city millage if inside town limits
- Use the correct ratio: primary vs. rental
- Multiply it out — or ask us
This is part of our bigger guide, A Homeowner's Guide to Property Taxes in Summerville.
Want the tax estimate on a home you're eyeing?
Tell us the address and we'll help you figure out what the yearly bill would look like.
Ask for an estimate