How to Calculate Boot in a 1031 Exchange and the Tax You Owe

Boot Is Taxable Gain, Recognized in the Year of Exchange

Boot is any value received in a 1031 exchange that is not like-kind real property. The IRS taxes boot as recognized gain in the calendar year the exchange closes, regardless of how much gain was successfully deferred on the rest of the transaction. Under IRC Section 1031(b), the recognized gain equals the lesser of the realized gain or the total boot received. The deferred portion of the gain carries into the replacement property's adjusted basis.

Two categories create boot. Cash boot is money or cash equivalents received at settlement, net cash proceeds from a sale that exceed the purchase price of the replacement property, or equity withdrawn from the transaction. Mortgage boot, sometimes called debt relief boot, arises when the loan on the relinquished property exceeds the loan on the replacement property. The IRS treats that debt reduction as if the investor pocketed the difference in cash.

How to Calculate Realized Gain Before Measuring Boot

The realized gain is the starting figure. Without it, you cannot determine how much of your boot is actually taxable.

The formula:

Realized Gain = (Net Sale Price of Relinquished Property) - (Adjusted Basis of Relinquished Property)

Net sale price is the contract price minus selling costs such as commissions, title fees, and transfer taxes. Adjusted basis is original purchase price plus capital improvements minus accumulated depreciation claimed.

Example: An investor sells a rental property for $1,200,000. Selling costs total $72,000, producing a net sale price of $1,128,000. Original purchase price was $600,000. The investor added $80,000 in improvements and claimed $110,000 in depreciation over 12 years. Adjusted basis equals $600,000 + $80,000 - $110,000 = $570,000. Realized gain equals $1,128,000 - $570,000 = $558,000.

How to Calculate Cash Boot

Cash boot equals net proceeds not reinvested into the replacement property.

Cash Boot = (Net Sale Proceeds Received) - (Purchase Price of Replacement Property)

If the replacement property costs more than the net proceeds, cash boot is zero, not negative. Negative boot does not create a tax benefit.

Example continued: The investor from the section above reinvests into a replacement property priced at $1,050,000. Net proceeds after selling costs were $1,128,000. Cash boot equals $1,128,000 - $1,050,000 = $78,000.

Recognized gain equals the lesser of realized gain ($558,000) or total boot ($78,000). The recognized gain on this exchange is $78,000. The remaining $480,000 in realized gain defers into the replacement property's adjusted basis.

How to Calculate Mortgage Boot

Mortgage boot triggers when the relinquished property carries more debt than the replacement property. The investor effectively receives debt relief, which the IRS treats as cash received.

Mortgage Boot = (Mortgage Paid Off on Relinquished Property) - (New Mortgage on Replacement Property)

Cash boot and mortgage boot offset each other in one direction only. Additional cash invested into the replacement property reduces mortgage boot dollar for dollar. Excess mortgage boot does not reduce cash boot.

Example: An investor sells a property carrying a $400,000 mortgage and buys a replacement property with a $310,000 mortgage. Mortgage boot equals $400,000 - $310,000 = $90,000. If this investor also paid $40,000 in additional cash toward the replacement property at closing, that $40,000 reduces the mortgage boot to $50,000. Total boot recognized is $50,000.

At a 23.8% combined federal long-term capital gains rate plus the 3.8% net investment income tax (applicable to high-income investors), $50,000 in boot produces a federal tax bill of $13,650 in the year of the exchange.

Depreciation Recapture Stacks on Top of Boot

Depreciation recapture under IRC Section 1250 is taxed at your ordinary income rate, capped at 25%, separate from the long-term capital gains rate. When an exchange produces recognized gain, the IRS allocates recognized gain first to depreciation recapture, then to capital gain.

Example: An investor has $110,000 in accumulated depreciation and triggers $78,000 in recognized boot gain. The IRS taxes the entire $78,000 as depreciation recapture at the investor's ordinary rate, not at the preferential long-term capital gains rate. For a top-bracket investor, the 25% cap applies. Federal tax owed equals $78,000 x 25% = $19,500, before state tax. Had the investor assumed no depreciation existed, that $3,900 difference (between 25% and the 20% long-term rate applied to $78,000) would have come as a surprise at filing.

Three Practical Ways to Eliminate or Reduce Boot

Reducing boot requires action before or at closing, not after.

Buy up in value. The replacement property's purchase price must equal or exceed the relinquished property's net sale price. A $50,000 gap in price creates at least $50,000 in cash boot.

Match or increase debt. If you cannot increase the replacement mortgage, contribute additional personal cash to close the gap. Each dollar of additional cash contributed reduces mortgage boot by one dollar.

Avoid equity withdrawals before the exchange. Cash-out refinances completed within six months of a planned 1031 exchange can be recharacterized by the IRS as tax-motivated boot extraction. Maintain clear documentation showing the refinance had an independent business purpose.

Run Your Boot Tax Calculation Before You Close

Boot tax owed depends on your total income, filing status, depreciation history, and state of residence. A California investor in the top bracket owes an additional 13.3% in state tax on top of the federal figures above. That turns a $78,000 recognized gain into a combined liability exceeding $31,000 in some scenarios.

The CalcMoney Income Tax Calculator lets you model recognized gain as ordinary income or capital gain, layer in your existing income, and see your marginal rate before you commit to an exchange structure. Run the numbers before closing, not after the qualified intermediary distributes proceeds.

Calculate your 1031 boot tax liability now →

You Might Also Like

• How to Calculate the Exact Tax Savings From a 1031 Exchange
• How to Calculate 1031 Exchange Boot and Tax Owed
• How to Calculate 1099 Income After All the Taxes You Actually Owe

Results are estimates for informational purposes only. Consult a licensed financial professional before making financial decisions.