The Cobb County property tax estimator is a free tool on the Cobb County Tax Commissioner’s website that projects your county tax bill from your home’s fair market value. You can find it at cobbtax.gov/property/tax_estimator.php. When you open it, the tool asks whether you’re working from a recently received assessment notice: answering “Yes” routes current owners to a calculator tied to their latest assessed value, and “No” opens a version for buyers or anyone estimating without a notice in hand.1Cobb County Tax Commissioner. Cobb County Tax Commissioner – Property Tax Estimator
What You Need Before You Run It
Three pieces of information drive the calculation, and having them ready saves you from guessing.
The first is your property’s fair market value. Cobb County’s Board of Tax Assessors sets this figure and prints it on your Annual Assessment Notice, which typically goes out in early June. If you don’t have the notice, look up your parcel on the Board of Tax Assessors’ website using the address or parcel ID.
The second is your tax district. Properties in unincorporated Cobb pay a fire district levy of roughly 2.99 mills; properties inside Acworth, Austell, Kennesaw, Marietta, Powder Springs, or Smyrna pay a city tax instead, set by each municipality.2Cobb County Georgia. Taxation
The third is which exemptions you qualify for. Exemptions reduce the value the tax rate is applied to, so leaving one out understates or overstates the bill by real money. More on the specific exemptions below.
How the Estimator Does the Math
The tool runs a calculation you can reproduce by hand. Georgia law taxes only 40% of a home’s fair market value, and that percentage is fixed statewide.3Justia. Georgia Code 48-5-7 – Assessment of Tangible Property4Georgia Department of Revenue. Property Tax Valuation So a $400,000 home has an assessed value of $160,000; a $550,000 home, $220,000.
From that assessed value, subtract your exemptions to get a net assessed value. Then multiply by the millage rate expressed as a decimal. One mill equals $1 of tax per $1,000 of assessed value.5Georgia Department of Revenue. Property Tax Millage Rates
A worked example: a $400,000 home is assessed at $160,000. Subtract a $10,000 Cobb basic homestead exemption and you’re at $150,000. At a combined rate of 29 mills (0.029), that’s $4,350 in county-side tax, before adding fire district or city levies.
The total millage rate is a stack: the county general fund rate set by the Board of Commissioners, the Cobb County School District rate set by the Board of Education, and either the fire district rate or a city rate.6Cobb County Tax Commissioner. Millage Rates – Property Tax
Limitations to Know Before Trusting the Output
Two things the estimator will not do for you.
It covers county taxes only. If your property sits inside one of the six cities, the estimator does not include your city tax, and you’ll need to contact that city’s tax office separately.1Cobb County Tax Commissioner. Cobb County Tax Commissioner – Property Tax Estimator
It also uses the most recently approved millage rates, which means the timing of your estimate matters. New rates aren’t approved until late July or early August, once every taxing authority has voted. Any estimate you run before then reflects the prior year’s rates. For the closest read on what you’ll actually owe, run the tool after August.
The estimator likewise doesn’t handle agricultural classifications or special exemptions outside the standard categories.
Homestead Exemptions That Change the Answer
To claim any homestead exemption for a given tax year, you must own and occupy the home as your primary residence and file your application by April 1 of that year. Miss the deadline and the exemption is off the table until the following year.
Standard Exemptions Most Owners Get
The state homestead exemption under O.C.G.A. § 48-5-44 takes $2,000 off the assessed value used for county and school taxes.7Georgia Department of Revenue. Property Tax Homestead Exemptions Cobb County’s own basic homestead exemption adds $10,000 in the county general and county school general categories.8Cobb County Tax Commissioner. Cobb County Homestead Exemptions These stack, and there’s no income test for either.
Senior and Disability Exemptions
Age and disability unlock several larger exemptions in Cobb:
- Owners who turn 62 by January 1 receive a full exemption from school general and school bond taxes, with no income limit.8Cobb County Tax Commissioner. Cobb County Homestead Exemptions
- Owners 65 and older can claim a $4,000 state senior exemption in the state, county bond, and fire district categories if combined household income for the prior year was $10,000 or less, excluding Social Security and retirement income.8Cobb County Tax Commissioner. Cobb County Homestead Exemptions
- The Cobb County disability exemption is $22,000 across all tax categories except the state levy.8Cobb County Tax Commissioner. Cobb County Homestead Exemptions
- A floating inflation-proof exemption is available at age 62 with household income under $30,000. It freezes the county tax assessment at the base-year level so appreciation doesn’t raise your county bill. It replaces other county exemptions rather than stacking, and it doesn’t apply to school or municipal taxes.9Justia. Georgia Code 48-5-47.1 – Homestead Exemptions for Senior Citizens
Veteran and Surviving Spouse Exemptions
Veterans with a service-connected disability qualify for an exemption that adjusts annually based on a rate set by the U.S. Secretary of Veterans Affairs. The 2026 maximum is $126,526. The benefit continues for an unremarried surviving spouse or minor children who keep living in the home.10Georgia Department of Veterans Service. Disabled Veteran Homestead Tax Exemption A separate exemption is available under O.C.G.A. § 48-5-52.1 for surviving spouses of service members killed in action.8Cobb County Tax Commissioner. Cobb County Homestead Exemptions
If the Estimate Comes Back Higher Than It Should
The estimator only reflects the fair market value you feed it, so if the number looks off, the place to start is the assessment itself. You have 45 days from the mailing date on your Annual Assessment Notice to file an appeal with the Cobb County Board of Tax Assessors.11Justia. Georgia Code 48-5-311 – Creation of County Boards of Equalization A written letter identifying the property and stating that you disagree with the value is enough to open the appeal; no lawyer or formal form is required at that stage.
The strongest evidence is recent sale prices of comparable homes near you, ideally from the past one to two years, matched on square footage, lot size, and condition. Documented damage, contractor repair estimates, or an independent appraisal also carry weight. What the appeal cannot address is the tax rate itself or how the revenue is spent; the question is strictly whether the assessed value is accurate.
When the Bill Is Due
Cobb County property tax bills are due by October 15 each year, and payments must be received or postmarked by that date.12Cobb County Tax Commissioner. Tax Bills Issued So the practical workflow: after August, once new millage rates are posted, run the estimator with your current fair market value and confirmed exemptions. That gives you the closest read on what you’ll owe when the bill lands.