The number on the bill is from 1996
Chester County’s assessed values come from a countywide reassessment that used 1996 values and took effect for the 1998 tax year. There has not been another one. Every bill you will ever see here starts from that number, and it has nothing to do with what you paid last month.
That is why a Chester County tax bill looks alarming and then turns out not to be. A 33-mill school rate applied to a 1996-era assessment is a different animal from 33 mills applied to a 2026 price. It also means the mills themselves carry no information until you know the base they sit on.
The ratio and the factor
Two published numbers bridge the gap.
The county sets a common level ratio of 30.6%. It applies to appeals heard by the Board of Assessment Appeals during 2026, which produce bills issued in 2027, and to interim appeals effective July 1, 2026 through June 30, 2027.
The Pennsylvania Department of Revenue publishes the matching factor, 3.27, for documents accepted July 1, 2026 through June 30, 2027. It is used on deeds where there is no genuine sale price to tax.
The arithmetic runs both directions and takes ten seconds:
- Price to assessment: $600,000 x 0.306 = about $183,600.
- Assessment to implied market value: assessment x 3.27.
So a house assessed at $150,000 implies a market value near $490,500 in the state’s eyes. If you just paid $430,000 for it, that is a conversation worth having.
What that does to an appeal
Take what you paid, multiply by 0.306, and compare the result to the assessment on the parcel record. If the assessment sits materially above that figure, there is an argument to make. If it sits below, an appeal invites attention you probably do not want.
Run the arithmetic before you assume there is a case. The Board of Assessment Appeals decides it, not the calculator, and the hearing calendar drives when any change reaches a bill: appeals heard in 2026 land on 2027 bills. Interim appeals — the ones triggered by new construction or an improvement — run on the July-to-June window the ratio is published for.
Three lines, one bill
County millage for 2026 is 5.164 mills. Municipal millage is usually the smallest line on the bill, and the spread across the county is wide.
| Municipality | 2026 millage |
|---|---|
| Malvern Borough | 4.670 |
| Easttown Township | 4.859 |
| Tredyffrin Township | 4.313 |
| West Whiteland Township | 2.000 |
| Uwchlan Township | 1.025 |
| East Whiteland Township | 0.895 |
| Willistown Township | 0.280 |
Uwchlan’s 1.025 mills for 2026, adopted in December 2025, was the township’s first general real estate tax increase since 1989, covering a deficit of roughly $854,000. Caln Township’s 2026 budget presentation proposed 6.840 mills, most of the increase in the fire levy; treat that as proposed, and confirm the adopted figure with the township.
Add the three lines together and you get the totals the county publishes: 35.9340 mills in Malvern Borough, 40.6134 in Tredyffrin, 41.1594 in Easttown, 32.1590 in East Whiteland, 31.5440 in Willistown.
School millage, 2026-27
This is the line that moves a payment.
| District | 2026-27 millage |
|---|---|
| West Chester Area | 24.16 |
| Great Valley | 26.1000 |
| Tredyffrin/Easttown | 31.1364 |
| Downingtown Area | 33.0268 |
| Unionville-Chadds Ford (Chester County side) | 34.95 |
| Kennett Consolidated | 36.2036 |
West Chester Area’s rate is up 3.3% and the district put the average increase at about $148 a year. Downingtown Area adopted 33.0268 mills in May 2026, up 3.5%, with a homestead credit of $354.38. Tredyffrin/Easttown adopted 31.1364 mills in June 2026, an increase the district estimated at about $388 a year for an average homeowner, with a homestead reduction near $346. Great Valley’s 26.1000 mills came with a homestead exclusion of $8,286.02 of assessed value.
Several districts had not published a 2026-27 rate we could confirm at the time of writing. The county’s own tax rate sheet carries all of them and is the place to check yours.
Earned income tax is its own line
It never appears on the property tax bill, and it lands on the same household budget.
Tredyffrin Township levies no earned income tax at all — 0% resident and 0% non-resident in the state’s 2026 tax register, which is unusual anywhere in this county. Easttown Township started levying 0.5% on January 1, 2025. Malvern Borough and Willistown are at 1%, East Whiteland at 0.8%. The local services tax is $52 in all of them.
That is the whole picture: an assessment from 1996, three millage lines applied to it, an earned income tax beside it, and a ratio published to translate the lot into today’s money. Have the parcel number and the township to hand, and a licensed Pennsylvania lender calls you back, usually the same business day, and builds the tax line from the millage that actually applies to it.