Delaware County Property Taxes, Explained
Delaware County reassessed countywide in 2021, so its numbers read differently from most of its neighbors: assessments were reset to market value that year, and the millage is scaled to those larger assessments. Here’s what you’ll pay, how the state’s ratio keeps it comparable county to county, and how the bill breaks down across every school district that taxes homes here.
County and municipal millage: 2026. School millage: 2025-26 adopted budgets (districts adopt the next year's budgets by June 30; we update when PDE certifies the statewide file in the fall). Common Level Ratio: STEB 2025 (54.64%). A new CLR takes effect each July 1, and we update then.
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Search homes for sale in Delaware CountyWhy the millage looks low here
Delaware County reassessed countywide in 2021: every assessment was reset to that year's market value and has been frozen since. Prices have risen, so the state currently puts assessments at about 54.64% of today's value. Millage here applies to those much larger assessments, which is why it looks low next to a county still assessing on a decades-old base year. The comparable number is the effective rate below.
The effective rate fixes that: millage multiplied by the county's Common Level Ratio (54.64%), expressed as a percentage of a home's real market value. That is the figure NookLocal uses everywhere, so you can compare Delaware County to anywhere else.
- 2021
- Assessment base year
- 54.64%
- Common Level Ratio
- 4.609
- County millage
- 0.25%
- County levy, effective
Effective property-tax rate by school district
Typical total rate (county plus median municipality plus school) as a share of market value, and the annual bill on a $450,000 home. Cheapest first. Districts based in a neighboring county appear with their Delaware County rate. Rates vary by municipality within a district, so open a district for its full range.
| School district | School rate | Total rate | ~Tax / $450,000 |
|---|---|---|---|
| West Chester AreaBased in Chester County; this is its Delaware County rate. | 0.62% | 0.87% | $3,928 |
| Marple Newtown | 0.68% | 1.07% | $4,809 |
| Rose Tree Media | 0.87% | 1.21% | $5,423 |
| Radnor Township | 0.86% | 1.26% | $5,684 |
| Chester-Upland | 0.79% | 1.36% | $6,098 |
| Garnet Valley | 1.09% | 1.39% | $6,257 |
| Haverford Township | 1.07% | 1.58% | $7,119 |
| Penn-Delco | 1.13% | 1.60% | $7,215 |
| Unionville-Chadds FordBased in Chester County; this is its Delaware County rate. | 1.05% | 1.61% | $7,235 |
| Springfield | 1.21% | 1.78% | $8,019 |
| Interboro | 1.43% | 2.05% | $9,220 |
| Wallingford-Swarthmore | 1.70% | 2.17% | $9,746 |
| Ridley | 1.61% | 2.19% | $9,850 |
| Upper Darby | 1.45% | 2.36% | $10,605 |
| Chichester | 1.65% | 2.41% | $10,844 |
| Southeast Delco | 1.78% | 2.54% | $11,446 |
| William Penn | 1.80% | 2.66% | $11,953 |
What a buyer should expect
Pennsylvania does not reassess a home just because it sells, so the millage and assessment usually carry over to you. The exception: buy well above a home’s implied market value and the school district can file an assessment appeal that raises your bill. For a specific home, the property tax calculator and every listing page do the exact math, including an appeal-risk check. The Common Level Ratio table explains the conversion, and the School District Value Matrix weighs these rates against school quality.
Common questions
Why does Delaware County property tax millage look low compared to nearby counties?
Because Delaware County reassessed countywide in 2021, its assessed values were reset to market value then and the state currently puts them at about 54.64% of today's value, so the millage doesn't need to be scaled up the way it is in counties assessing on a decades-old base year. The comparable number across counties is the effective rate: millage multiplied by the CLR, the share of a home's real market value you pay each year.
How are Delaware County property taxes calculated?
Your bill is the sum of three millage rates, county (4.609), your municipality, and your school district, applied to your home's assessed value. Because Delaware County assesses on 2021 values, NookLocal converts every rate to an effective percentage of market value using the 2025 Common Level Ratio (54.64%), so you can compare what you'll pay across towns and districts.
Will my property taxes change when I buy a home in Delaware County?
Pennsylvania does not reassess a property simply because it sells, so your millage and assessment usually carry over. But if you buy well above the home's implied market value, the school district can file an assessment appeal that raises your bill. Every NookLocal listing shows the recomputed tax at the current rate, plus an appeal-risk check.
Which Delaware County school district has the lowest property taxes?
Among the districts we cover that tax homes in Delaware County and operate public schools, West Chester Area (based in Chester County; the figure is its Delaware County rate) carries the lowest typical total rate: about 0.87% of market value, roughly $3,928 per year on a $450,000 home. William Penn is the highest, at about 2.66%, roughly $11,953 per year. Rates also vary by municipality within a district, and the table above lists each one.
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Tax data: Delaware County assessment office, adopted school budgets, and the Pennsylvania State Tax Equalization Board (Common Level Ratio). Effective rates assume an assessment at the current CLR, the right baseline for a purchase. Figures do not subtract homestead or farmstead exclusions, which lower the school portion for many owner-occupants; apply for those after you buy. Deemed reliable but not guaranteed; verify with the county and district before transacting.