Delaware Tax Estimator

There is no single Delaware property tax rate

Delaware does not have one rate — it has 3. They run from 0.33% in Sussex County to 0.74% in New Castle County, with the median county at 0.46%. That is the first thing to understand before comparing Delaware against anywhere else: a state average is an average of things that do not resemble each other.

The range here is comparatively tight — about 2.2 to one between the extremes — which usually means Delaware funds a large share of school costs at state level rather than leaving districts to raise it locally. Where the state carries more, local rates converge.

On a $400,000 home the difference between the two ends of Delaware is roughly $1,639 a year, every year you own it. Pick your county below rather than reasoning from the state figure.

How Delaware compares with the rest of the country

Delaware is cheap by national standards. Its median county charges 0.46% against a national median of 0.84% — well under, and in the case of its lowest counties, a fraction of what a typical American county charges.

For scale, US effective rates run from about 0.08% to 3.64% across the 3,132 counties with published data — more than twenty to one on the same property, decided almost entirely by which side of a line it stands on.

A more useful measure than the rate is what it takes out of a local income. Across Delaware counties the median bill averages about 2.0% of median household income.

The Delaware rules that decide your bill

Start with what is actually taxed, because Delaware does not reach it by a single fixed fraction. Delaware assessed at 100% of a base year, and the base years had gone unmoved for four decades: Sussex County last reassessed in 1974, New Castle in 1983, Kent in 1987. A 2020 Court of Chancery ruling forced a statewide reassessment — Kent billed on new values in 2024, New Castle and Sussex in 2025 — and in New Castle assessed values rose by an average of 433%. If you are looking at Delaware figures from before that, they describe a system that no longer exists.

Delaware’s Senior School Property Tax Credit covers 50% of regular school property tax, capped at $500, from age 65 — but the residency test is unusually harsh and got harsher: anyone who established domicile from 1 January 2018 onward needs TEN consecutive years in the state before qualifying. Applications close 30 April.

These are Delaware rules and they apply in every county in the state. What varies locally is the rate, not the relief — so if you qualify and have not claimed it, your county assessor is where that gets fixed, not the state.

Property tax and income tax in Delaware, together

Delaware taxes income as well as property, at graduated rates up to 6.60%. The two are set by different authorities — income by the state, property by your county — and they answer different questions, so it is worth adding them rather than comparing them.

States trade one off against the other. A low income tax is often paired with heavier property tax and the reverse, which is why a comparison built on a single tax so frequently gives the opposite of the right answer. Our income tax calculator covers the Delaware side of that.

What a house actually costs in Delaware, at four prices

At the median county rate of 0.46%, a $250,000 home carries about $1,145 a year, a $400,000 home $1,832, a $600,000 home $2,748, and a $900,000 home $4,122. Property tax is close to linear in value, which income tax is not — doubling the house roughly doubles the bill.

But the median is the wrong number to plan with, because you do not buy in the median county. That same $600,000 house costs $1,988 a year in Sussex County and $4,447 in New Castle County — a difference of $2,458 every year, on identical property, under identical state law.

Over a ten-year hold that gap compounds to $24,582 before any rate increase. It is larger than most buyers' entire closing-cost budget, and it is decided by which side of a line on a map the house sits on. That is the case for looking up the county rather than the state.

One caution on all four figures: they apply the effective rate to the full purchase price. Where the state assesses at a fraction of market value, or caps how fast the assessed value can climb, your first-year bill and your fifth-year bill will differ from this — the sections below say exactly how, for Delaware.

All 3 Delaware counties, one by one

Delaware has few enough counties that the whole list fits in a paragraph, which makes the usual advice — look up your county — unusually easy to follow here. Sussex County taxes at 0.33%, about $1,093 a year on the state's median home value of $329,800; Kent County taxes at 0.46%, about $1,510 a year on the state's median home value of $329,800; New Castle County taxes at 0.74%, about $2,444 a year on the state's median home value of $329,800.

The gap between Sussex County and New Castle County is 0.41% of value, or $1,351 a year on that same house — $13,512 across a decade of ownership. With so few jurisdictions the choice is unusually consequential: there is no near-identical neighbouring county to fall back on.

A short list also means the county rate hides more than it does elsewhere. Where a state has only a handful of counties, the meaningful variation moves down a level — to municipalities, school districts and special districts inside each one — and two houses in the same county here can differ by more than the counties differ from each other. Use these figures to set expectations, and the local assessor's roll to settle them.

Each rate above is median tax paid divided by median home value in that county, from the Census American Community Survey. It reflects what owners actually paid, exemptions and assessment practice included — not a millage from a rate table.

Market value, assessed value and the number on your bill

Delaware assessed at 100% of a base year, and the base years had gone unmoved for four decades: Sussex County last reassessed in 1974, New Castle in 1983, Kent in 1987. A 2020 Court of Chancery ruling forced a statewide reassessment — Kent billed on new values in 2024, New Castle and Sussex in 2025 — and in New Castle assessed values rose by an average of 433%. If you are looking at Delaware figures from before that, they describe a system that no longer exists.

Delaware does not apply one statewide ratio, which means the published rate and the assessed base have to be read together for your own jurisdiction. A rate quoted without the base it applies to tells you nothing comparable.

This is exactly why every rate on this site is an EFFECTIVE rate: tax actually paid divided by the home's market value. It is the only figure that survives comparison across state lines, because it has the assessment ratio, the exemptions and the millage already folded into it. A nominal millage does not.

It also explains a common shock. Assessment ratios and reassessment cycles differ, so a state can reassess every year, every three years, or on sale only. Where reassessment is infrequent, the correction when it finally arrives is not a rate increase — it is several years of market movement landing at once, and appealing the rate rather than the value is arguing the wrong point.

Appealing a Delaware assessment: what it is worth

You cannot appeal the tax rate — that is set by budget votes you have no standing to challenge individually. What you can appeal is the assessor's opinion of your property's value, and that is a factual claim you can be right or wrong about.

The arithmetic decides whether it is worth your afternoon. On the state's median home of $329,800, the bill runs about $1,510 a year. A 10% reduction in assessed value is worth roughly $151 a year, and because the corrected value carries forward it is nearer $755 across five years. Under $60 a year, the paperwork rarely pays; over $400, it usually does.

What wins is comparable sales, not hardship. Three to five recent arm's-length sales of genuinely similar properties — same neighbourhood, similar size, age and condition — near your valuation date. What loses is what the bill does to your budget, what the previous owner paid, or that the rate went up. Assessors decide value; none of those speak to value.

Also check the record itself before arguing valuation, because errors are commoner than contested opinions: square footage that includes an unfinished basement, a bathroom that does not exist, a garage counted twice, land area from a survey predating a lot split. A factual correction is usually granted without a hearing.

The deadline in Delaware: Applications close 30 April. Miss it and there is generally no remedy until the following cycle, whatever the merits — property tax appeal windows are short and strictly applied, and they typically start from the date the notice was mailed rather than the date you opened it.

Relief for older owners in Delaware

Delaware’s Senior School Property Tax Credit covers 50% of regular school property tax, capped at $500, from age 65 — but the residency test is unusually harsh and got harsher: anyone who established domicile from 1 January 2018 onward needs TEN consecutive years in the state before qualifying. Applications close 30 April.

This matters more than the headline rate for anyone retiring in place. Property tax is the one major tax that does not fall when your income does — the house is worth what it is worth whether you are earning $120,000 or drawing $38,000 from a pension, and a bill that was 3% of income while working can be 9% of it afterwards.

Relief of this kind almost always has to be applied for, is usually income-tested, and in several states takes the form of a deferral rather than a discount: the tax is postponed and becomes a lien recovered when the property is sold or transferred. A deferral solves a cash-flow problem and reduces what heirs receive. Both can be the right choice; they are not the same choice, and the paperwork rarely spells out which one you are signing.

Check it against the income-tax side too. A state that treats retirement income generously and property harshly, or the reverse, can come out very differently once both are counted — which is what the comparison further down this page is for.

The ten-year figure, which is the one that decides a purchase

A single year's property tax is a number people accept without much thought. The decade is the number that changes decisions, because unlike a mortgage it never amortises away and unlike income tax it does not fall when your income does.

On Delaware's median home value of $329,800, held ten years with assessed value rising 4% a year, the median county collects about $18,135. The cheapest county in the state collects $13,122 over the same period and the dearest $29,345 — a spread of $16,223 on identical property, decided entirely by location.

The same house at the national median rate of 0.84% would run $33,146 over ten years, so the median Delaware county costs about $15,011 less across the decade than a typical American county would.

Set that against the mortgage to see the weight of it. On a $329,800 purchase the ten-year property tax bill in the median county is roughly 7% of the amount financed at 80% loan-to-value — before insurance, before maintenance, and before any millage increase. It is the largest recurring cost of ownership after interest, and the only one that a district can raise without asking you.

Treat the figure as an order of magnitude rather than a forecast. It assumes the county's current effective rate holds, and rates move with district budgets and with reassessment cycles. What it is reliable for is the comparison: the gap between two counties is far more durable than either absolute number.

How the bill is paid, and what happens if it is not

Most owners with a mortgage never pay this directly. The servicer collects roughly $126 a month alongside principal and interest on the state's median bill, holds it in escrow, and pays the county when it falls due. The consequence is that a rise reaches you as a change in your monthly payment months after the fact, with no obvious connection to the assessment notice that caused it.

Read the annual escrow analysis when it arrives. It shows the bill actually paid, and it is the cheapest way to catch an assessment you would have appealed had you noticed — by the time the payment changes, the appeal window for that year has usually closed.

Owners without a mortgage pay the county directly, generally in two instalments; Delaware's calendar is set out above. Late payment carries interest set by statute rather than by the county, and it is not small — rates in the region of 1% a month are common, which is above most credit card debt on an annualised basis.

Unpaid property tax is also secured against the house itself, which is what separates it from every other tax. States permit a tax lien, and eventually a tax sale, at the end of a statutory redemption period. It is slow and heavily noticed, so it is nearly always avoidable — but the mechanism means an unpaid property tax bill can never simply be written off the way an unpaid income tax debt sometimes is.

Five ways a Delaware property tax estimate goes wrong

Using the state average. Delaware has 3 counties with published rates and they do not resemble one another. The state figure is an average of things that are not alike, and applying it to a house in New Castle County understates the bill by $934 a year.

Applying the millage to the market price. Where assessed value is a fraction of market value, multiplying the published rate by the purchase price overstates the result — sometimes by half. Use an effective rate, which already accounts for the base.

Assuming exemptions are automatic. A homestead exemption generally has to be claimed after purchase, and nothing on the bill announces that it is missing. Buyers who never file pay the unexempted figure for as long as they own.

Comparing property tax in isolation. Delaware also taxes income, so a property-only comparison against a no-income-tax state reaches the wrong conclusion in one direction — and against a high-income-tax state, the wrong conclusion in the other. Both taxes or neither.

Trusting the listing's tax line. It is the seller's bill, carrying their tenure and their exemptions. Where a sale triggers reassessment it is not a forecast of yours, and it is the single most common reason a first full-year bill arrives higher than budgeted.

How a Delaware property tax bill is put together

Your bill is not one rate. It is the sum of every authority that reaches your parcel — the county, the school district, the city or township, and often a fire, library or water district — each setting its rate separately and all of them added together. That is why two houses of identical value on opposite sides of a district line inside the same county owe different amounts, and both figures are correct.

The effective rates on this site are a different and more comparable thing: the median tax actually paid in a county divided by its median home value, from US Census data. That number can be compared across state lines. A millage rate cannot, because assessment practice differs from state to state — and Delaware is a good example of why.

Use the county figure to compare places and to sanity-check an escrow estimate. Use your assessor's roll to find out what you owe.

Delaware property tax questions

What is the average property tax rate in Delaware?

The median Delaware county has an effective rate of 0.46%, but the state average hides a lot: rates run from 0.33% in Sussex County to 0.74% in New Castle County. Use your own county's figure rather than the state one.

Which Delaware county has the lowest property tax?

Sussex County, at 0.33%. The highest is New Castle County at 0.74% — a difference of about 2.2 to one on the same house.

How much is property tax on a $400,000 home in Delaware?

At the median county rate of 0.46%, roughly $1,832 a year, or about $153 a month once it is in escrow. In Sussex County it would be nearer $1,326 and in New Castle County nearer $2,964.

Does Delaware have an income tax too?

Yes — graduated rates up to 6.60%, on top of the property tax on this page. Worth adding both before comparing Delaware against another state.

Do I need a parcel number to estimate Delaware property tax?

No. Your county assessor's own estimator generally asks for one, which is fine if you already own the property and useless if you are deciding whether to buy it. This works from the home value instead — though for the binding figure, the assessor remains the authority.