1031 Exchange Calculator
Estimate how much tax a 1031 exchange defers on your investment property sale — including boot, your new basis in the replacement property, and a side-by-side comparison against selling outright. Built for a standard delayed exchange through a Qualified Intermediary, the way most 1031s actually happen.
New to 1031 exchanges? Read our full 1031 exchange guide first. Selling without an exchange? See our Capital Gains Tax Calculator, or all our calculators.
Glossary
Boot is any value you pull out of the exchange rather than reinvest — cash you keep, or debt relief you don’t replace with an equal or greater new mortgage (unless you offset that with additional cash). Boot is taxable in the year of the exchange; everything else is deferred.
If you pay off a $500,000 mortgage on the property you’re selling but only take on a $300,000 mortgage on the replacement, that $200,000 of debt relief is treated the same as if you’d pocketed $200,000 in cash — it’s boot, and it’s taxable, even though you never actually touched the money. Adding your own cash into the replacement purchase can offset this.
Your new basis is lower than the replacement property’s purchase price by exactly your deferred gain — that deferral isn’t forgiven, it’s carried forward. When you eventually sell the replacement property without another exchange, that deferred gain becomes taxable then, on top of whatever new gain you’ve made since.
NY State and NYC both conform to federal 1031 deferral — no separate state add-back at the time of the exchange. Nonresident sellers normally face mandatory NY withholding at closing (Form IT-2663), but a properly documented exchange is exempt from that withholding. If your replacement property is out of state and you might sell it later without another exchange, confirm the details with your accountant — the treatment of NY-sourced gain deferred into an out-of-state property isn’t something we’re confident enough to state as a fixed rule here.
This models the standard case: one relinquished property, one replacement property, through a Qualified Intermediary — the large majority of real-world 1031s. It does not model reverse exchanges, improvement/construction exchanges, or exchanges involving multiple relinquished or replacement properties. Work with a Qualified Intermediary for any of those.