New Castle County, DE Property Tax: $2,444/yr (2026)
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The effective property tax rate in New Castle County is 0.74% of assessed home value. On a home at the county median value of $329,800, that works out to about $2,441 per year, or $203 per month. New Castle County is located in central Delaware, and is home to approximately 573,030 residents.
About New Castle County
New Castle County covers approximately 426.3 square miles in Delaware. The county is home to about 573,030 residents living in roughly 235,057 housing units, of which 65.0% are owner-occupied. The median household income is $89,901, and the median home was built in 1975.
New Castle County borders Kent County, Cecil County, Kent County, Gloucester County, Salem County — useful comparisons if you're considering nearby areas with potentially different tax rates.
How Property Taxes Work in Delaware
Property taxes in Delaware are administered at the county level. Each county sets a millage rate applied to the assessed value of real property — the effective rate above accounts for any partial assessments and exemptions already built into the local tax base. Assessed value can differ meaningfully from current market value depending on how often the county reassesses and what fraction of market value it uses.
Most counties in Delaware offer exemptions that reduce the taxable assessed value: homestead exemptions for primary residences, senior exemptions, disability exemptions, and veteran exemptions are common. These reduce your effective rate below the county-wide average shown here. Contact the New Castle County Assessor's office to learn which exemptions apply to your property and when to file.
New Castle County vs. Neighboring Counties
| Location | Eff. Rate | Median Home | Annual Tax |
|---|---|---|---|
| New Castle County, DE | 0.74% | $329,800 | $2,441 |
| Delaware state average | 0.51% | — | $1,682* |
| Kent County | 0.46% | $290,600 | $1,331 |
| Cecil County | 0.98% | $311,800 | $3,059 |
| Kent County | 0.94% | $307,100 | $2,896 |
| Gloucester County | 2.81% | $283,500 | $7,964 |
| Salem County | 3.03% | $223,000 | $6,757 |
| US national average | 1.10% | $281,900 | $3,101 |
*State average annual tax computed at New Castle County's median home value of $329,800. Source: US Census ACS 2023 5-year estimates.
Frequently Asked Questions
How does New Castle County's property tax rate compare to the rest of Delaware?
At 0.74%, New Castle County is higher than the Delaware state average of 0.51%. On a home at the county median of $329,800, that means about $2,441 per year — versus $1,682 at the state average rate, a difference of $759 per year. Compared to the national average of 1.10%, New Castle County is below average.
What's a typical annual property tax bill in New Castle County?
For a home at the county median value of $329,800, the annual property tax in New Castle County is approximately $2,441 — or about $203 per month. For a home worth $494,700, expect around $3,661 per year. For a $659,600 home, approximately $4,881 per year. Use the calculator above to estimate taxes for any assessed value.
Where do I appeal a New Castle County property tax assessment?
Property assessment appeals in New Castle County are handled by the New Castle County Assessor's office. Most jurisdictions require filing within 30–90 days of receiving your assessment notice — confirm the specific deadline with the assessor's office before submitting, as deadlines and procedures vary by county. A successful appeal can reduce your assessed value and lower your tax bill for the current and future tax years.
What exemptions are available in New Castle County?
Delaware counties commonly offer homestead exemptions for owner-occupied primary residences, senior citizen exemptions for qualifying homeowners aged 65 and older, exemptions for disabled residents, and veterans' exemptions. Each exemption reduces your assessed taxable value, which in turn reduces your effective tax rate below the county-wide 0.74% shown here. Contact the New Castle County Assessor's office to confirm which exemptions are available and the application deadlines.
Data sources: US Census Bureau ACS 2023 5-Year Estimates, US Census Gazetteer (2024), County Adjacency File