Greater Princeton Property Tax and Tax Appeal Guide
Most homeowners who think about appealing their assessment never file, and most who do file have not run the one calculation that decides the outcome. This guide gives you the current rates and ratios for eight Greater Princeton towns, then walks through the test New Jersey actually applies.
Why comparing tax rates between towns misleads people
Every New Jersey town publishes a general tax rate, stated per $100 of assessed value. It is the number people quote, and on its own it tells you almost nothing, because towns assess at wildly different fractions of market value.
South Brunswick is the clearest example in this region. Its general tax rate is 5.578, more than double Princeton's 2.733, which makes it look like the most heavily taxed town on the list. It is not. South Brunswick assesses property at roughly 30 percent of market value, so once you adjust, its effective rate is 1.938 percent, lower than Princeton's neighbors and below Lawrence's 2.376 percent.
The effective tax rate is the number to compare. It expresses tax as a percentage of true market value, which is what you are actually paying on what your home is actually worth.
Rates and ratios, eight towns
General and effective rates are the 2025 figures certified by the New Jersey Division of Taxation. The average ratio and common level range are from the state's Chapter 123 certification for tax year 2026, originally certified October 1, 2025 and amended by the New Jersey Tax Court on January 30, 2026.
| Town | General rate | Effective rate | Avg ratio | Common level range |
|---|---|---|---|---|
| Princeton | 2.733 | 1.814% | 62.64% | 53.24 to 72.04 |
| South Brunswick | 5.578 | 1.938% | 29.62% | 25.18 to 34.06 |
| Montgomery | 3.438 | 2.060% | 56.24% | 47.80 to 64.68 |
| West Windsor | 3.162 | 2.080% | 63.45% | 53.93 to 72.97 |
| Plainsboro | 2.766 | 2.294% | 75.88% | 64.50 to 87.26 |
| Hopewell Township | 3.129 | 2.343% | 71.31% | 60.61 to 82.01 |
| Robbinsville | 3.488 | 2.345% | 62.01% | 52.71 to 71.31 |
| Lawrence | 3.165 | 2.376% | 73.80% | 62.73 to 84.87 |
Hopewell Borough (3.498 general, 2.545 effective) and Pennington (3.308 general, 2.420 effective) are assessed separately from Hopewell Township and run slightly higher.
The test that decides your appeal
New Jersey does not ask whether your assessment equals your market value. It asks whether your assessment is out of line with how the rest of your town is assessed. That comparison is governed by Chapter 123, and it works like this.
Divide your current assessment by what you believe your home is truly worth. That is your ratio. Compare it to your town's common level range in the table above, which is the average ratio plus or minus 15 percent. If your ratio sits inside the range, your assessment stands, no matter how far below market value it may be. If your ratio is above the upper limit, the board resets your assessment to your true value multiplied by the town's average ratio.
Take a Princeton home assessed at $900,000 that you can demonstrate is worth $1,100,000. Your ratio is 81.8 percent, above Princeton's upper limit of 72.04, so you qualify. The new assessment becomes $1,100,000 times 62.64 percent, or $689,040, a reduction of $210,960. At Princeton's general rate of 2.733 that is roughly $5,765 a year.
Now change one number. If that same Princeton home were assessed at $700,000 against a $1,100,000 market value, the ratio is 63.6 percent, comfortably inside the range. No relief, even though the assessment is $400,000 under market. The town is simply assessing you the way it assesses everyone.
Check your own ratio
Pick your town, enter your current assessment and what you believe the home was worth on October 1 of the pretax year. This applies the Chapter 123 test described above.
Estimate only, not legal or tax advice. Uses the 2026 Chapter 123 ratios and 2025 general rates in the table above. The implied value divides your assessment by the town average ratio and is a rough check, not an appraisal.
The risk nobody mentions
Chapter 123 runs in both directions. If your ratio comes in below the lower limit of the common level range, the county board can raise your assessment to true value times the average ratio. Filing an appeal opens your assessment to review, and the outcome is not capped at no change.
This is the main reason to run the ratio math before filing rather than after. If your home has appreciated faster than your town's assessments have been updated, which describes a lot of Greater Princeton property right now, you may be sitting comfortably inside or below the range and an appeal would work against you.
Deadlines and where to file
The standard deadline is April 1 of the tax year, or 45 days from the date your municipality mailed assessment notices, whichever is later. Notices generally go out at the end of January, so April 1 governs in most years. In a municipality that completed a revaluation or reassessment for that year, the deadline moves to May 1. Added and omitted assessments have their own December 1 deadline.
Missing the date ends the matter. There is no late filing and no discretion to accept one.
Most appeals go to your County Board of Taxation. If your property is assessed above $1,000,000 you may file directly with the New Jersey Tax Court instead, which is the usual route for higher-value homes because the evidentiary process is more thorough. For added assessments the direct-to-Tax-Court threshold is $750,000 of aggregate assessed value.
What evidence actually works
Comparable sales, and specifically sales that closed near the valuation date. New Jersey assesses as of October 1 of the pretax year, so a 2026 appeal is argued on what your home was worth on October 1, 2025. A sale from this spring is less useful than one from last autumn, which surprises people.
Bring three to five genuinely comparable closed sales: same town, similar size, similar age and condition, adjusted for real differences. Active listings are not evidence. Your own purchase price can be, if the purchase was recent and at arm's length. Photographs of condition problems help when the argument is that your home is in worse shape than the assessment assumes.
What does not work is arguing that your taxes went up, that your neighbor pays less, or that you cannot afford the bill. The only question before the board is your assessment relative to your town's common level.
A sensible order of operations
Start by finding your current assessment on your tax bill or your municipal assessor's page. Get a defensible opinion of market value as of October 1 of the prior year. Divide one by the other and compare the result to your town's range above. If you are above the upper limit by a meaningful margin, the appeal is worth preparing. If you are inside the range, it is not, and you have saved yourself the filing fee and the risk.
Many towns also offer an informal review with the assessor before the formal filing, which is worth a call. And if you are weighing an appeal alongside a possible sale, note that a successful reduction lowers your assessment, not your market value, and the two are separate conversations with a buyer.
For how PILOT agreements shift the tax picture in specific developments, see our guide to PILOT agreements and property taxes.
This is general information, not legal or tax advice. Rates and ratios change annually. Confirm current figures with your municipal assessor or your County Board of Taxation before filing. Sources: New Jersey Division of Taxation, 2025 General Tax Rates; New Jersey Division of Taxation, Certification of Average Ratios and Common Level Ranges for Tax Year 2026.
What is the deadline to appeal property taxes in New Jersey?
April 1 of the tax year, or 45 days from the date assessment notices were mailed, whichever is later. In municipalities that completed a revaluation or reassessment for that year the deadline is May 1. Added and omitted assessments have a separate December 1 deadline. Late filings are dismissed automatically.
How do I know if I have a case?
Divide your assessment by your home's true market value, then compare that ratio to your town's common level range. If the ratio is above the upper limit, the assessment gets reset to market value times the town's average ratio. If it falls inside the range, your assessment stands even if it is well below market value.
Can an appeal increase my assessment?
Yes. If your ratio falls below the lower limit of the common level range, the county board can raise your assessment to true value times the average ratio. That is why the ratio calculation belongs before the filing, not after.
Which Greater Princeton town has the lowest property taxes?
By effective tax rate, which measures tax against true market value, Princeton is lowest at 1.814 percent, followed by South Brunswick at 1.938 percent and Montgomery at 2.060 percent. Comparing general tax rates instead is misleading, because towns assess at very different fractions of market value.
Why is South Brunswick's tax rate so high?
Its general rate of 5.578 is high because South Brunswick assesses property at roughly 30 percent of market value. Once adjusted, the effective rate is 1.938 percent, among the lower rates in the region. The general rate and the assessment ratio have to be read together.
What evidence do I need for a tax appeal?
Three to five comparable closed sales from your town, similar in size, age and condition, that closed near October 1 of the pretax year, since that is the valuation date. Active listings do not count. Photographs documenting condition issues help. Arguments about affordability or what a neighbor pays are not relevant to the board's test.
Not sure what your home is actually worth?
The ratio math only works with a defensible market value. We will pull the comparable sales for your property so you can run the numbers before the deadline.