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1031 Exchange Rules Calculator

Calculate your exact deferred tax gain and find the minimum required trade-up rules to execute a perfectly tax-free 1031 exchange.

Relinquished Property Details

Relinquished Property Sales Price ($)

The final gross sale price of the old property you are exiting.

Original Cost Basis ($)

What you originally paid for the old property, plus any major capital improvements.

Total Depreciation Taken ($)

The cumulative sum of annual depreciation expenses you deducted from your taxes over the years. This lowers your basis and increases your taxable gain via "recapture".

Outstanding Mortgage Balance ($)

Total Realized Gain Deferred

$600,000

Amount successfully shielded from IRS

Strict Relinquished Value Rules:

Min. Replacement Value:$1,000,000

To defer 100% of taxes without cash boot, you must trade equal-to or higher in value.

Min. Replacement Debt:$400,000

Your new mortgage must equal or exceed old mortgage to avoid mortgage boot liability.

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What is IRS Section 1031 Like-Kind Exchange Tax Deferral Mechanics?

A 1031 Exchange (named after Internal Revenue Code Section 1031) allows real estate investors to defer the entire capital gains tax liability by selling an investment property and reinvesting the proceeds into a like-kind replacement property of equal or greater value within 180 days. The exchange is not a tax elimination — it is a tax deferral that carries the adjusted basis forward into the replacement property. The deferred gain is only recognized when the final property in the chain is sold without another 1031 exchange, or when the property passes to heirs and receives a stepped-up basis at death, potentially eliminating the deferred gain entirely.

Mathematical Foundation

Realized Gain (Capital Gains Recognition)

Gain_{realized} = Price_{sale} - Basis_{adjusted}

Price_{sale}

= Net sales price of the relinquished property after closing costs and commissions.

Basis_{adjusted}

= Original purchase price plus capital improvements, minus accumulated depreciation (Section 1250 recapture).

Gain_{realized}

= The total taxable capital gain that would be owed without the 1031 exchange.

Boot (Taxable Shortfall)

Boot = \max(0,\; Price_{sale} - Price_{replacement}) + Cash_{received}

Boot

= Any non-like-kind value received in the exchange — either cash kept (cash boot) or a reduction in purchase price below the sale price (mortgage boot). Boot is taxable in the year of the exchange.

Price_{replacement}

= Purchase price of the replacement property. Must equal or exceed the sale price to fully defer.

Cash_{received}

= Any sale proceeds not reinvested through the Qualified Intermediary.

Laws & Principles

The Equal-or-Greater Rule: To achieve 100% tax deferral, the replacement property's purchase price must be equal to or greater than the net sales price of the relinquished property, AND all net equity must be reinvested. Any shortfall — whether from a lower purchase price (mortgage boot) or cash pocketed (cash boot) — is taxable in the year of the exchange, up to the realized gain.
The 45/180 Day Hard Clock: From the day you close on the sale of your relinquished property, you have exactly 45 calendar days to identify up to 3 replacement properties in writing to your Qualified Intermediary (the 3-property rule), and exactly 180 calendar days to close on the replacement. These deadlines are absolute — no extensions exist for personal circumstances, only presidentially declared disasters. Missing either deadline disqualifies the entire exchange.

Step-by-Step Example Walkthrough

" An investor sells a rental duplex for $600,000 (adjusted basis: $350,000 after depreciation). They want to fully defer the $250,000 capital gain by exchanging into a larger apartment building. "

1. Calculate realized gain: $600,000 sale - $350,000 basis = $250,000 capital gain.
2. Tax liability without exchange: $250,000 × 23.8% (15% LTCG + 3.8% NIIT + 5% state) = $59,500 owed immediately.
3. For full deferral, replacement must be ≥ $600,000 and all equity must be reinvested.
4. Investor purchases $720,000 apartment building using the full $600,000 proceeds + new financing.
5. Boot received: $0 (replacement price exceeds sale price, all equity reinvested).
6. New basis in replacement property: $350,000 (original basis carries forward).

Final Result: The investor defers the entire $59,500 tax bill and deploys all $600,000 into the larger building. The adjusted basis of $350,000 carries forward — the deferred gain will only be recognized if the apartment is eventually sold without another 1031 exchange. If held until death, heirs receive a stepped-up basis, potentially eliminating the deferred gain entirely.

Quick Answer: What is a 1031 Exchange?

A 1031 Exchange (named after IRS Section 1031) lets real estate investors defer capital gains taxes by selling one investment property and reinvesting the proceeds into a "like-kind" replacement property. To fully defer all taxes, you must reinvest into a property of equal or greater value, roll over all equity, and close on the replacement within 180 days of selling.

Fast example: Selling a $500,000 rental property with $150,000 in capital gains? A 1031 Exchange can defer the ~$35,700 federal tax bill (at 23.8% long-term rate), leaving the full $500,000 working in your next investment.

The 3 IRS Rules You Must Meet

Rule 1

Equal or Greater Value

The replacement property's purchase price must be equal to or greater than the net sales price of your relinquished property. Any shortfall is taxable "boot."

Rule 2

Reinvest All Equity

All net equity (proceeds minus closing costs and mortgage payoff) must be reinvested. Any cash you pocket — called "boot" — is taxable in the year of the exchange.

Rule 3

45/180 Day Deadlines — Hard IRS Deadlines

45 days to identify replacement properties in writing after closing the sale. 180 days to close on the replacement. These deadlines are absolute — no extensions granted except in presidentially declared disasters.

Real-World 1031 Exchange Examples

Rental House → Apartment Building (Fully Tax-Free)

Sale price: $450,000 · Adjusted basis: $200,000
Realized gain: $450,000 - $200,000 = $250,000
Tax owed (23.8%): $59,500 — fully deferred
Replacement: Buys $520,000 duplex with all equity rolled over
Boot received: $0 — complete tax deferral

→ $59,500 tax deferred, $450,000 fully deployed

Retail Unit → Warehouse (Partial Exchange with Boot)

Sale price: $600,000 · Basis: $300,000
Realized gain: $300,000
Replacement purchased: $550,000 warehouse
Boot received: $50,000 cash kept = taxable this year
Tax on boot (23.8%): ~$11,900 due now

→ $288,100 gain deferred; $11,900 tax due

1031 Exchange Tax Savings by Gain Bracket

Capital Gain	Federal Tax (23.8%)	State Tax (avg 5%)	Total Deferred
$100,000	$23,800	$5,000	$28,800
$300,000	$71,400	$15,000	$86,400
$750,000	$178,500	$37,500	$216,000
💡 State tax rates vary significantly. California imposes 13.3% on gains — consult a tax advisor for your state. Depreciation recapture is taxed at 25% and is also deferrable via 1031.

Pro Tips & Common Mistakes

Do This

✓Hire a Qualified Intermediary (QI) before closing. You cannot touch the proceeds yourself. A licensed QI must hold funds between the sale and purchase — this is a strict IRS requirement, not optional.
✓Identify up to 3 replacement properties. The IRS "3-property rule" lets you identify 3 candidates by day 45 without restriction. This gives you negotiating flexibility if your first choice falls through.

Avoid This

✗Don't miss the 45-day identification deadline. Receiving proceeds without a QI in place, or identifying properties after day 45, disqualifies the entire exchange — the full gain becomes taxable immediately.
✗Don't exchange personal-use or dealer properties. Your primary residence, vacation homes (without qualified rental history), and properties held primarily for sale (fix-and-flip) do not qualify as like-kind under Section 1031.

Frequently Asked Questions

How long do I have to complete a 1031 Exchange?

You have 45 calendar days from the sale closing date to identify candidate replacement properties in writing to your Qualified Intermediary, and 180 calendar days to close on the replacement property. Both deadlines run concurrently from day 1 of the sale. There are no extensions for personal circumstances — only a presidentially declared disaster can extend these timelines.

Can I do a 1031 Exchange on my primary residence?

No. Section 1031 applies only to property held for investment or business use. Your primary residence does not qualify. However, if you have a property that was previously a rental and you later moved into it, there are strategies (under Section 121 combined with 1031) that may allow a partial exclusion — consult a tax attorney before attempting this.

What happens to depreciation recapture in a 1031 Exchange?

Depreciation recapture (taxed at 25% under IRS Section 1250) is also fully deferred in a qualifying 1031 Exchange. Your adjusted basis carries forward into the replacement property. This means the recapture tax is not eliminated — it is postponed until you eventually sell without doing another 1031, or until the property passes to heirs (who receive a stepped-up basis at your death, potentially eliminating the deferred gain entirely).

What is "boot" in a 1031 Exchange?

"Boot" is any non-like-kind value you receive in the exchange — typically cash boot (proceeds you pocket instead of reinvesting) or mortgage boot (when your replacement property has a lower mortgage than the property you sold, and you don't compensate with additional cash). Boot is taxable in the year of the exchange, up to the amount of your realized gain. To avoid boot, ensure the replacement property value equals or exceeds the relinquished property value AND that all equity is reinvested.