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1031 Exchange Calculator

A Section 1031 exchange lets you roll the gain from one investment property into the next instead of paying tax today. Enter your sale, your basis, and your replacement property to see what you defer — and whether you're creating taxable boot.

Educational calculators — always consult a licensed professional before making financial decisions.

Your exchange

01The property you're selling

The gross contract price, and the commissions, title, escrow and transfer costs that come off it. What's left is what the exchange has to reinvest.

Sale price of the property you're selling?

The contract price on the relinquished property.

$
$10K$100M
Selling costs on the sale?

Commissions, title, escrow, and closing fees.

$
$0$10M

Net sale price $752,000

02Your basis

Purchase price plus improvements, less every year of depreciation claimed — your tax return or CPA's depreciation schedule has both figures.

Adjusted basis in the property you're selling?

Original purchase price + improvements − accumulated depreciation.

$
$0$100M
Accumulated depreciation taken?

Total depreciation claimed over your entire hold.

$
$0$100M

Realized gain $402,000

03Replacement property

Buying below your net sale price means some proceeds leave the exchange as taxable cash boot.

$
$0$100M
04Mortgage debt

The payoff on your closing statement, and the loan on the new property. A smaller new loan is debt relief — mortgage boot.

Mortgage balance paid off on the sale?

Debt cleared at the closing of the property you're selling.

$
$0$100M
New mortgage on the replacement property?

Debt you're taking on the property you're buying.

$
$0$100M

Mortgage boot $0

05Tax rates

Your bracket sets the rate on the gain above depreciation recapture, which is taxed separately at up to 25%. Add a state rate if yours taxes capital gains.

Your long-term capital gains rate?

The US long-term brackets are 0%, 15%, and 20%.

Most common

State tax rate on the gain?

Leave at 0 if your state has no income tax.

%
0%20%

Tax Deferred With a 1031

$72,300

vs $72,300 owed if you sell outright

Realized gain$402,000
Gain deferred into new property$402,000
Taxable bootNone
Tax due now on boot$0
Carryover basis in new property$548,000
Fully deferred — no boot. You're reinvesting all the proceeds and replacing at least as much debt, so the whole gain rolls forward. Remember: deferred, not forgiven — the gain follows you into the new property through a reduced basis.

If You Sell Outright

Net sale price (after selling costs)$752,000
− Adjusted basis$350,000
= Realized gain$402,000
Depreciation recapture @ 25%$120,000 → $30,000
Remaining capital gain @ 15%$282,000 → $42,300
Total tax if you sell$72,300

Boot Check

Net proceeds to the intermediary$502,000
Cash the replacement property needs$550,000
Cash boot (proceeds not reinvested)$0
Mortgage boot (debt relief)$0
Total boot$0

The Clock

Identify replacement property within45 days
Close on replacement property within180 days

Both deadlines run from the closing of the property you sell, and they run concurrently — the 180 days is the total period, not 45 + 180. Neither can be extended.

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Email me the detailed report

A full PDF breakdown of these numbers — yours to keep or hand to a contractor.

Educational estimate — not tax or legal advice. 1031 exchanges are technical and mistakes are expensive: a missed deadline or touching the proceeds yourself can disqualify the whole exchange and trigger the full tax bill. This tool ignores net investment income tax, partial-year and state-specific rules, and non-real-property elements. Consult a CPA and a Qualified Intermediary before you list the property.

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How it works

1

Enter the sale

Input sale price, adjusted basis, accumulated depreciation, and selling costs.

2

Add the replacement

Enter the new property price, the mortgage you're paying off, and the new mortgage.

3

Read your deferral

See tax deferred vs selling outright, any taxable boot, and your carryover basis.

How a 1031 exchange actually works

A Section 1031 like-kind exchange lets you sell one investment property and buy another without paying the tax on your gain right now. The critical word is defer, not forgive. Nothing is written off. The gain is parked, and it follows you into the next property. What you get is the use of the tax money — the full proceeds keep working in real estate instead of a chunk leaving for the IRS at every trade. Over a career of moving up from a duplex to a fourplex to a small apartment building, that compounding is the entire point.

The clock is the part people get wrong. From the day the property you're selling closes, you have 45 days to identify your replacement property in writing and 180 days to close on it. Both deadlines are measured from that same closing date and they run concurrently — the 180 days is the total period, not 45 days plus another 180. Burn all 45 days deciding and you have 135 left to actually close. There is no extension for a slow lender, a failed inspection, or a seller who backs out. This is why serious exchangers line up candidate properties before they list.

You cannot touch the money. The proceeds must go to a Qualified Intermediary, hired before the sale closes, who holds the funds and buys the replacement property on your behalf. Taking constructive receipt — having the check routed to you or your own account, even for a day, even untouched — disqualifies the exchange. It is the most common way an otherwise clean deal falls apart, and it's entirely preventable with a phone call made a week earlier.

Boot is what trading down costs you. To defer the whole gain, you generally need to buy at or above your net sale price and replace at least as much debt as you paid off. Fall short and the shortfall is boot, which is taxable. Cash boot is proceeds you don't reinvest; mortgage boot is debt relief when the new loan is smaller than the old one. A partial exchange still works — you recognize gain only up to the boot and defer the rest — but people are routinely surprised that paying down debt on the new property generated a tax bill.

Depreciation rides along. The depreciation you claimed lowered your basis every year, which is why long-held rentals have far larger gains than owners expect. That slice is taxed as unrecaptured Section 1250 gain at up to 25% on a sale — and a 1031 defers it too, rather than erasing it. Your basis in the new property is its price minus the deferred gain, so the untaxed gain is baked in from day one, along with smaller future depreciation deductions.

A 1031 is not the route for a home you have lived in. Like-kind exchange treatment is for investment or business property; a principal residence is handled under Section 121 instead, which excludes up to $250,000 of gain — $500,000 on a joint return — rather than deferring it. If the property you are selling was your home for part of the time you owned it, work the residence side out on the home sale capital gains tax calculator first: the ownership and use tests, the reduced exclusion when a move was forced, and the same Section 1250 recapture all behave differently there, and the answer decides whether an exchange is even the cheaper path.

"Swap till you drop." As a general principle, exchanges can be chained indefinitely, and under current law heirs receive a stepped-up basis at death — which is why some investors never sell outright at all. That's a long-horizon estate strategy that turns on rules which can change, so treat it as context rather than a plan, and build it with an estate attorney. In the meantime, judge the replacement property on its own merits: run its cap rate and its full ROI before the tax tail wags the investment dog. A deferred tax bill is a poor reason to overpay for a worse building.

By RealCost Editorial TeamReviewed by RealCost Editorial TeamLast updated September 5, 2026 with September 2026 data

A 1031 exchange defers capital gains tax by rolling proceeds from one investment property into another. Two deadlines govern it and neither is extendable: 45 days to identify replacement property, and 180 days to close. Miss either and the exchange fails and the whole gain becomes taxable in that year.

The two clocks that decide everything

Both periods start on the day you transfer the relinquished property, and they run concurrently rather than sequentially — the 45 days are the first 45 of the 180.

  • ·45-day identification period. You must identify replacement property in writing within 45 days of the sale closing.
  • ·180-day exchange period. You must receive the replacement property within 180 days of the sale — or by the due date of your tax return for that year including extensions, whichever is earlier. That second condition catches people whose sale falls late in the calendar year, because the return deadline can arrive well before day 180.

Both are stated by the IRS and neither bends for a failed inspection, a financing delay or a seller who walks. That is why identifying more than one candidate property within the 45 days is standard practice rather than indecision.

What actually qualifies now

The scope of Section 1031 narrowed considerably. Since January 1, 2018 it applies only to real property held for productive use in a trade or business or for investment. Exchanges of personal property, equipment, vehicles and intangibles no longer qualify at all.

Two further limits matter in practice. Property held primarily for sale — a flip, or a developer's inventory — does not qualify, because it is not held for investment. And a personal residence does not qualify; that is the domain of the Section 121 exclusion, which is a different provision with different rules. Our cost to sell calculator handles the primary-residence case.

"Like-kind" is broad within real property: an apartment building can be exchanged for raw land, a retail unit for a warehouse. The constraint is the character of the holding, not the type of building.

What this calculator does not tell you

  • ·Deferral is not forgiveness. The deferred gain carries into the replacement property's basis. Sell that without another exchange and the whole accumulated gain becomes taxable.
  • ·Boot. Cash or debt relief received in the exchange is taxable to that extent, even if the rest qualifies.
  • ·The qualified intermediary is mandatory. You cannot take receipt of the proceeds. Touching the money ends the exchange.
  • ·State treatment varies. Some states impose their own rules and clawbacks on exchanges out of state. This calculator models federal deferral only.

Reporting is its own step: a completed exchange is declared on Form 8824 for the year the relinquished property was transferred, which is how the deferred gain and the adjusted basis of the replacement property are established on the record. An exchange that is executed correctly but never reported is not a deferral.

This is one of the few areas of property tax where the deadlines are absolute and the penalty for a technical failure is the entire tax bill. Treat the output here as a sizing tool and engage a qualified intermediary before the relinquished property closes, not after.

Methodology

Deferral is computed from the gain you enter and the structure of the exchange. The 45-day identification and 180-day exchange periods, and the post-2017 restriction of Section 1031 to real property held for business or investment, are quoted from the IRS pages listed below. This calculator models federal deferral and does not model boot, depreciation recapture rates, or state-level rules.

Sources

  1. IRS — Like-Kind Exchanges, Real Estate Tax Tips — accessed 2026-09-05
  2. IRS — Instructions for Form 8824, Like-Kind Exchanges — accessed 2026-09-05

The 1031 clock — both deadlines run from the same closing

MilestoneDeadlineMeasured from
Identify replacement property in writing45 daysClosing of the relinquished property
Close on replacement property180 days totalClosing of the relinquished property
Time left to close after using all 45 days135 daysEnd of the identification period
Extensions availableNone—

The 180 days is the total exchange period, not 45 + 180. Proceeds must be held by a Qualified Intermediary throughout — taking constructive receipt disqualifies the exchange.

Frequently asked questions

What are the 45-day and 180-day deadlines in a 1031 exchange?

You have 45 days from the closing of the property you sell to identify your replacement property in writing, and 180 days from that same closing to complete the purchase. Both clocks start at the same moment and run concurrently — the 180 days is the total period, not an extra 180 on top of the 45. So once you use the full 45 days to identify, you have 135 days left to close. Neither deadline can be extended, and missing either one generally means the exchange fails and the full tax comes due.

Do I really need a Qualified Intermediary?

Yes. You cannot take constructive receipt of the sale proceeds at any point. A Qualified Intermediary must be engaged before the relinquished property closes and must hold the funds between the sale and the purchase. Having the proceeds routed to you, your attorney, or your own escrow — even briefly, even if you never spend a dollar — is one of the most common ways people accidentally blow an otherwise valid exchange. Set the intermediary up before you close, not after.

What is boot in a 1031 exchange?

Boot is any value you receive from the exchange that isn't like-kind replacement property, and it's taxable. It comes in two forms. Cash boot is sale proceeds you don't reinvest — money that ends up in your pocket instead of the new property. Mortgage boot is debt relief: if the new mortgage is smaller than the loan you paid off on the sale, the difference counts as value received. Trading down in price or debt is what triggers boot. The gain you recognize is the lesser of your boot and your total realized gain, so a partial exchange still defers the rest.

Does a 1031 exchange defer depreciation recapture too?

Yes. Depreciation recapture — the unrecaptured Section 1250 gain taxed at a maximum rate of 25% — is deferred along with the rest of the gain, not eliminated. This matters more than most investors expect, because depreciation reduces your adjusted basis every year you own the property. After a long hold, the recapture slice can be a large share of your total tax bill, and it rides forward into the replacement property with everything else.

What happens to my basis in the replacement property?

It carries over, reduced by the gain you deferred. Your basis in the new property is roughly its purchase price minus the deferred gain, rather than the full price you paid. That's the mechanism that makes deferral work: the untaxed gain follows you into the new property. Practically, it means lower depreciation deductions going forward and a larger gain waiting whenever you eventually sell without exchanging again.

What property qualifies as like-kind?

Since 2018, Section 1031 applies only to real property held for investment or productive use in a trade or business. Real estate is broadly like-kind to other real estate — an apartment building can be exchanged for raw land, a rental house for a strip mall. What does not qualify is your primary residence, a property held primarily for resale (a flip), and personal property such as vehicles or equipment, which lost 1031 eligibility in the 2017 tax law.

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1031 Exchange Calculator is built and maintained by the RealCostIQ editorial team. Cost ranges and rates are checked against published industry data and contractor quotes, and revised when the underlying figures move. Read our data methodology or more about who builds this. Every calculation runs in your browser — no account, and none of your inputs are stored.

Cost ranges and rates here are checked against contractor quotes and published industry data. If a number still looks off, email Support@RealCostIQ.com and we'll review and fix it.