Mansion Tax Calculator

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, which is often tiered rather than flat.

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.