Mansion Tax Calculator

Enter the sale price, threshold and rate to estimate the mansion tax due.

Result

How it is calculated

The rule is a cliff: tax = price × rate ÷ 100 if price ≥ threshold, otherwise 0. The price and threshold are in US dollars and the rate is a percentage that you enter yourself, as a single flat figure. The test uses "greater than or equal", so a sale exactly at the threshold is taxed, and when it applies the rate is charged on the entire price, not only on the part above the threshold. The effective rate shown is tax ÷ price × 100, which equals your rate when the tax applies and 0% when it does not. The tool does not know any jurisdiction's actual schedule, so tiered brackets, rates that rise with price, and taxes charged on the excess over a threshold are not modelled. The price must be above zero.

Worked example

A home sells for $1,200,000, the threshold is $1,000,000 and the rate is 1%. Since 1,200,000 is at least 1,000,000, the tax applies to the full price: 1,200,000 × 1% = $12,000.00. The Applies line shows Yes and the effective rate is 1.00%. Had the price been $999,999, the tax would be $0.00, while $1,000,000 jumps to $10,000.00, which shows how sharp the cliff is.

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Common mistakes

  • Typing the rate as a decimal. Enter 1 for one percent, not 0.01; 0.01 would be a hundredth of a percent and the tax would be tiny.
  • Assuming only the amount above the threshold is taxed. This tool charges the rate on the whole price once the threshold is reached, so it can overstate the tax in places that tax only the excess.
  • Using one rate for a place with tiers. If the schedule climbs at higher price bands, run the sale price with the band's own rate instead of a blended number.
  • Entering a price just under the threshold and expecting a small tax. Below the threshold the result is exactly $0.00, not a reduced amount.
  • Treating the output as the whole closing bill. Standard transfer tax, recording fees and any city surcharge are separate and have to be added by you.

Sources

About this calculator

A mansion tax is an additional real estate transfer or conveyance tax applied specifically to residential property sales above a set price threshold, layered on top of any standard transfer tax that already applies to all sales. New York State’s mansion tax, for instance, applies to residential sales of $1 million or more, and some cities such as New York City add their own supplemental tax with progressively higher rates at higher price tiers — so the tax owed depends on the sale price, the threshold that triggers it, and the applicable rate. Real schedules are often tiered, but this calculator takes a single rate that you enter.

This calculator applies the cliff-style rule: once the sale price reaches the threshold, the tax due is the full sale price × tax rate. Some jurisdictions instead tax only the amount above the threshold or use graduated brackets — the two readings differ hugely just past the threshold — so check which rule yours uses. Real estate buyers, sellers, and closing attorneys estimate this tax during deal negotiation and closing cost planning, since on a high-value sale it can add a substantial and easily overlooked line item to the buyer’s or seller’s closing costs; this calculator estimates the mansion tax due from a sale price, threshold, and rate.

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Comments (1)

  • Editorial team

    Because the rule is a cliff, this tool is most useful for testing a price just below and just at the threshold. Run both, and the gap shows what a seller's price concession would need to save the buyer in tax. It models one flat rate you type in, applied to the whole price, so where only the excess is taxed, multiply the amount over the threshold by the rate yourself. Which jurisdictions would you like to see supported with real schedules?

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