Delaware Property Tax Calculator (Assessed Value & Millage Rates)

Nationally, Delaware's #43 ranking, tied with Nevada, and 0.47% average effective rate put it among the ten lowest effective property tax rates in the country. That is noticeably below the national average of roughly 1.0%, based on the average effective rate across all 50 states. Compared with the rest of the South, which averages roughly 0.79%, Delaware lands well below its neighbors.

That revenue underwrites the basics (public schools, county government, emergency services), the same way it does across most of the South, though the specific mix of school, county, and municipal millage varies by jurisdiction within Delaware.

Assessments are handled at the county level in Delaware, where local appraisers periodically revalue residential and commercial parcels and apply the applicable millage rates; homestead exemptions and formal appeals remain the main levers available to individual owners looking to manage the bill, alongside any local bond measures voters approve along the way.

Delaware's oddity is age. For decades the three counties assessed property against base years from the 1970s and 1980s, so assessed values had almost no relationship to market prices, and court-ordered reassessments have only recently reset them. Nominal rates look tiny because the values they multiply were frozen for a generation.

None of that detail is asked for here. This calculator works one level up, applying Delaware's average effective property tax rate of 0.47% to the value you enter. That rate is the ratio of property taxes actually paid to home value across the state, so the assessment ratios, caps, and exemptions described above are already baked into it.

Working through it in order:

1. Start from the county's assessed value. That figure comes from the county's base year, which is why it may look nothing like a sale price.
2. Take off exemptions. Senior and disability exemptions reduce assessed value, and school tax credits reduce the bill for qualifying older owners.
3. Multiply by the effective rate. At 0.47%, a $400,000 home in Delaware comes to $1,880 a year before any exemption you enter above.
4. Divide by twelve for escrow. That same home works out to $156.67 a month set aside in a mortgage escrow account.
5. Compare it against your own bill. Comparing a Delaware nominal rate to another state's is meaningless without knowing which base year the assessment came from. Your county's number is the one that governs; this figure tells you whether it is roughly where a Delaware home of that value ought to land.

Using this calculator's baseline inputs: a $400,000 home in Delaware, taxed at the state's 0.47% average effective rate (rank #43 of 50 states, tied with Nevada).

1. Start with the assessed value. The home is assessed at its full $400,000.00 market value, with no homestead exemption applied in this baseline scenario.
2. Apply the effective rate. $400,000.00 × 0.47% = $1,880.00 in annual property tax, Delaware's statewide average effective rate.
3. Convert to a monthly escrow. Lenders typically collect property tax in twelve equal installments alongside principal and interest: $1,880.00 ÷ 12 = $156.67 per month.
4. Project a five-year hold. At a flat rate, five years of ownership totals $1,880.00 × 5 = $9,400.00, before any reassessment, exemption change, or millage increase.

At 0.47%, Delaware carries one of the lightest property tax burdens nationally, ranking #43 of 50 states, tied with Nevada, though actual bills still vary by county and municipality.

At 0.47% Delaware sits 43rd of 50, and the tier schedule reflects a single rate applied to every rung. No bracket, no cliff, no cap enters the Delaware path in this engine: taxable value is market value less whatever exemption you enter, and the annual figure is that number times 0.0047.

Where the sweep starts and ends. Row 1 values the property at $66,666.67 and returns $313.33 a year, $26.11 a month. Row 12 doubles the baseline to $800,000 and returns $3,760.00 a year, $313.33 a month. That symmetry is not a coincidence: on a flat rate the annual tax at the bottom rung and the monthly tax at the top rung land on the same $313.33.

The marginal figure. Each additional $10,000 of Delaware market value costs $47.00 a year, $3.92 a month. Moving from the $400,000 baseline to $410,000 takes the bill from $1,880.00 to $1,927.00. A $200,000 addition, taking the property to $600,000, costs $940.00 a year and brings the total to $2,820.00, still less than a $400,000 home costs in about forty other states.

The reverse question. A homeowner working to a $2,000 annual property tax ceiling can carry $425,531.91 of Delaware market value: the engine returns exactly $2,000.00 and $166.67 a month at that value. That is $25,531.91 of headroom above the $400,000 baseline, and it is the sort of margin that only exists in the low-rate states. The same $2,000 ceiling in Connecticut, at 1.66%, buys under $121,000 of house.

Where a Delaware bill actually comes from, and what that costs you here. Delaware's counties have historically assessed against decades-old base-year valuations rather than current market value, which is a large part of why the effective rate is so low. This engine does not reconstruct any of that. It never touches a base year, a county reassessment cycle, or a school district levy; it applies one statewide effective rate to the value you type. If your county has recently completed a court-ordered reassessment, the county's own figure is authoritative and this one is a benchmark.

The exemption field, and its limitation. A $10,000 entry drops taxable value to $390,000 and the bill to $1,833.00, a $47.00 saving that is identical to the marginal cost of $10,000 of value, because on a flat rate an exemption and a valuation reduction are the same operation. A $25,000 entry returns $1,762.50. The engine deducts this from market value directly, so a senior or disabled exemption granted against a county's assessed value cannot be entered at face value and expect to be right.

• Specific hyper-local county and municipal millage district variations within Delaware.
• Special assessment or improvement district charges. Some Delaware municipalities levy additional assessments on benefiting parcels for street, drainage, or sewer improvements on top of the base county and school millage; the specific list of districts varies by municipality.
• Commercial vs residential assessment classification differentials.
• Property tax appeal reductions or localized board of equalization adjustments.

• Confusing Market Fair Value with Assessed Basis: Some jurisdictions assess property at fractional ratios rather than 100% of market value.
• Failing to File Homestead Paperwork: Homestead exemptions are rarely automatic; homeowners must file timely paperwork with the county appraisal district.
• Underestimating Post-Sale Supplemental Assessments: Purchasing a newly constructed or reassessed property often triggers catch-up supplemental tax bills.
• Ignoring Property Tax Appeal Windows: Missing the annual 30-to-60 day statutory protest window forfeits the right to challenge over-assessed property values for that tax year.

• U.S. Census Bureau: American Community Survey (ACS) Real Estate Assessment Benchmark Data. census.gov/programs-surveys/acs
• Delaware Division of Revenue, the official state tax authority for Delaware rates, rules and forms. revenue.delaware.gov

Also consulted: New Castle, Kent, and Sussex County Assessment Offices: Property Tax Assessment Guidance.