By Lisa Sevajian, Realtor · Last updated October 14, 2026 · 8 min read

Assessed Value vs Market Value: Why Does Your House in MA or NH Have Two Different Numbers?

Everyone wants to know what their home is worth. I start with a different question.

The question is this. Which number do you mean? Your house has two, and they almost never match.

If that feels confusing, you aren't alone. Owners call me worried after a new assessment letter. Buyers get nervous when the town's number looks low next to the price. Sellers feel hurt when it looks high and buyers won't pay it.

Once you see how the two numbers work, a lot clicks into place. Your tax bill. Your price. Why a house down the street sold for more than the town said it was worth.

The town's number decides your tax bill. Buyers decide your price.

What's the difference between assessed value and market value?

Market value is what a buyer will pay for your house today. Nobody sets it in an office. Buyers set it, when they compare your house to every other home for sale and decide what it's worth to them.

Assessed value is the town's number. It exists for one reason, to figure your property tax. It doesn't decide what your house would sell for.

How does the town turn assessed value into a tax bill?

The math is simple. Take your assessed value, divide by 1,000, then multiply by the tax rate.

Here's an example with a real rate. Salem NH's 2025 rate was $18.16 per $1,000. So each $100,000 of assessed value cost about $1,816 a year in tax.

The rate isn't random. The town decides how much money it needs. The rate is whatever it takes to raise that amount from all the assessed value in town.

Why do the two numbers drift apart?

Because towns update on a schedule, and the market moves every day.

In New Hampshire, towns do a full revaluation about every five years. A revaluation means the town updates every property to match the market. In between, the town's number mostly sits still while prices keep moving.

In Massachusetts, values are set as of January 1 before each tax year, and assessors adjust them every year. The state reviews each town's values on a five-year cycle. So Massachusetts numbers tend to drift less, though they still trail the market.

What happened in Salem NH's 2026 revaluation?

Salem NH just showed how big the drift can get. Its last revaluation used values from April 1, 2021. The new one uses April 1, 2026.

The market didn't jump 51 percent overnight. The town's number was five years behind. The town says it plainly: a higher assessment doesn't mean your bill goes up by the same percent.

The new Salem NH rate gets set by the state later this fall. Until then, nobody knows your exact bill. Don't multiply your new value by the old rate. That rate was built for the old, lower values.

If values go up, why do tax rates go down?

Because the town still needs about the same pot of money. When every value grows, the rate shrinks to raise it.

Rates are per $1,000 of assessed value, from the NH Department of Revenue Administration.

Windham NH is the clearest case. After its 2025 revaluation, the town's total value rose 67 percent and the rate fell 37.5 percent. Same budget, bigger base, lower rate.

Here's the catch. A lower rate doesn't always mean a lower bill. Residential building values in Windham NH rose about 71 percent. Run the math, and a home that rose that much paid roughly 5 to 7 percent more, even with the big rate cut. Watch your bill, not just the rate.

Can you compare tax rates from town to town?

Not by the rate alone. Each town's rate sits on top of values from a different year.

Salem NH's 2025 rate sat on 2021 values. Windham NH's 2025 rate sat on fresh 2025 values. So the same house would carry very different assessments in each town. Comparing the two rates side by side gives you the wrong answer.

Here's the better way. Look up the assessed value of a real house you like in each town. Multiply by that town's current rate. Now you're comparing real bills. Derry NH is in the same spot this year, with new values mailed in late August and a new rate expected in November.

What does this mean if you're selling?

Buyers don't pay assessed value. They pay market value.

Most buyers I work with look at two or three towns, not one. They're shopping a monthly payment, and that payment includes taxes. So your house isn't only up against the one down the street. It's up against every similar home in the towns your buyer is searching.

That's why I price a home in this order. First, what sellers near you said yes to lately, for how much, why they picked that buyer, and what the buyer did to win. Second, every home for sale within about 10 miles in your price range, since that's what your buyer could choose instead. Third, the accurate similar sales from the last 30 days. The town's number isn't on that list.

What does this mean if you're buying?

Don't let a high assessment scare you, and don't let a low one excite you. Neither one is the price. The price is what buyers are paying for similar homes right now.

Ask two questions about any house you like. When did this town last do a revaluation? Is a new tax rate coming? A house in a town that's due for one can see its assessment jump soon after you buy. Then run the monthly payment with taxes in it. That's the number you'll live with.

What if you think your assessment is too high?

You can ask for an abatement. An abatement is a request to lower your assessment, with proof.

In New Hampshire, the deadline is March 1, after you get your fall tax bill. Salem NH and Derry NH both list it. In Massachusetts, you file with your town's assessors by the due date of the first actual tax bill for that year.

A big jump alone isn't proof. You need to show your value is higher than what your home would sell for. Accurate similar sales are that proof. Text me your address and our team will pull the recent sales near you, so you can see if you have a case.

This is general information, not legal, tax or lending advice. Check with your attorney, lender and CPA before you decide.

I'll guide you home.

Lisa Sevajian