1031 Exchange Calculator
Estimate the gain a 1031 exchange defers, the cash and mortgage boot that stays taxable, the new property's basis, and the 45-day and 180-day deadlines. Enter the sale, your basis and the replacement purchase, and the closing date for the deadlines; add your own tax rates for an estimate of the tax deferred. Every step of the working is shown.
Your numbers
The relinquished property.
Commission, closing costs, intermediary fee.
What you paid, plus improvements, minus the depreciation you took. Your tax records or depreciation schedule have it.
All the depreciation you claimed (or could have claimed). Used for the basis when you work it out, and for the tax estimate below.
Your own money, beyond the exchange funds.
Optional, for the tax estimate. Federal, as a percent.
Optional. The IRS caps unrecaptured section 1250 gain at 25%.
Optional. 0 if your state has no income tax.
The exchange must close by day 180 or this due date, whichever is earlier.
The day the old property transfers. Both deadlines count from this day.
Gain deferred
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- Gain taxed now (recognized)
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- Realized gain
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- Cash boot (exchange money not reinvested)
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- Mortgage boot (debt relief not replaced)
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- Basis of the replacement property
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- Exchange funds held by the intermediary
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- Smallest replacement price that can defer all the gain
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- Identify replacement property by (day 45)
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- Close on the replacement by (day 180)
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An estimate, not tax advice. Use a qualified intermediary and a tax professional: the exchange agreement, your return and your state's rules decide the real numbers.
The deadlines count calendar days and are not extended for weekends or holidays. Identify in writing, signed and delivered before day 45.
The calculation runs in your browser and ParrotNotes does not store your numbers. They sit in the page address so you can bookmark or share the result.
How the 1031 exchange numbers work
A 1031 exchange lets you sell investment or business real estate and buy other US real estate without paying tax on the gain now. The gain is the sale price, less selling and exchange costs, less your adjusted basis (what you paid plus improvements, minus the depreciation you took). If you get cash or less debt out of the exchange, that part, the boot, is taxed this year; the rest is deferred.
Worked example: you sell for $800,000, pay $40,000 in commissions and closing costs, have a $400,000 adjusted basis and pay off a $300,000 mortgage. The realized gain is $360,000 and the intermediary holds $460,000. You buy a $700,000 property with a $250,000 loan, which needs $450,000 of the $460,000. The $10,000 left over is cash boot, and the $50,000 drop in debt is mortgage boot, so $60,000 of the gain is recognized and $300,000 is deferred. The new property's basis is $700,000 − $300,000 = $400,000.
How to defer all of the gain
From the same formulas: buy a replacement worth at least the net sale price (the price less selling costs), spend all of the exchange money on it, and replace the old mortgage with a new one at least as large or with your own cash. In the example that means a replacement of $760,000 or more, all $460,000 reinvested and the rest financed. The calculator shows the smallest price that can defer everything.
The 45-day and 180-day deadlines
Both periods start on the day the old property transfers. The identification period ends at midnight on the 45th day after it; the exchange period ends at midnight on the 180th day or on the due date of your return for the year of the sale, including extensions, whichever is earlier (Treas. Reg. §1.1031(k)-1(b)(2)). The regulation's own example: a transfer on November 16, 1992 gives December 31, 1992 for identification and May 15, 1993 for day 180.
Identify in a written document you sign, sent before the 45 days run out. You can name up to three properties of any value, or more if their total value is no more than 200% of what you sold. The calculator uses April 15 (or October 15 with an extension) of the year after the sale for an individual's calendar-year return, even when the 15th falls on a weekend, because the earlier date is the safe one. For another kind of return, enter its due date.
What this calculator leaves out
It treats the exchange as one property sold and one bought, with no other property, personal property or seller financing in the deal. It does not handle related-party exchanges (a two-year holding rule applies), reverse or improvement exchanges, a primary residence or a property held mainly for resale, or state rules. US and foreign real property are not like-kind. If the money reaches your hands before you buy, the deal can be treated as a sale, which is why a qualified intermediary holds it. Not tax advice.
Sources, read on 2026-11-01. Your tax professional and the exchange agreement have the final say:
- 26 U.S.C. §1031 (Cornell LII): like-kind real property, the 45-day and 180-day rule, boot, basis
- Treas. Reg. §1.1031(k)-1: identification and exchange periods, written identification, the three-property and 200% rules
- Treas. Reg. §1.1031(d)-2: how liabilities and cash offset, with the worked examples
- IRS Instructions for Form 8824, Part III: realized, recognized and deferred gain and the new basis
- IRS Topic 409, Capital gains and losses: unrecaptured section 1250 gain taxed at a maximum 25%
- IRS, When to file: April 15 for calendar-year individuals
- IRS, Get an extension to file your tax return: until October 15
This page is about the tax side of a swap. To compare the old and new property on income, use the cap rate calculator; for the commission that goes into the selling costs, the real estate commission calculator; and to run a rehab and refinance deal, the BRRRR calculator.
More for real estate agents and investors: Commercial real estate broker: the job and its notes, Tips for new real estate agents, Investor meeting notes.
The exchange plan gets made in a meeting
The numbers here are the start of a conversation with the client, the intermediary and the tax professional: which properties to identify, how much debt to replace, what happens if a deal falls through. Record that meeting in ParrotNotes and you get a transcript and a summary with the dates and figures everyone agreed.
Get Started FreeRelated tools
- Cap Rate CalculatorWork out a property's cap rate from net operating income and price, the value at a target cap rate, cash on cash return and price per square foot.Open the tool
- Real Estate Commission CalculatorSee the total commission on a sale, the listing and buyer sides, the brokerage split and what the agent nets after fees.Open the tool
- BRRRR CalculatorRun the numbers on a buy, rehab, rent, refinance, repeat deal: cash in, cash-out refinance, cash left in the deal, monthly cash flow and cash-on-cash return.Open the tool