Sell and Pay the Tax vs a 1031 Exchange: The Numbers Side by Side

The ratio that decides it is tax divided by the equity the sale would hand you

Gain is the wrong denominator. What you give up by selling is the cash the closing would put in your account, so the number that matters is the tax as a share of that cash, and two sellers with similar-sounding gains can land at 12.5% and 29.1%.

The spread comes from three things: how much of the gain is depreciation taxed at the 25% cap, whether your other income pushes the balance from the 15% band into the 20% band, and whether modified adjusted gross income clears the surtax threshold. Leverage matters too, because a large payoff shrinks the equity while leaving the gain untouched.

Both cases below assume 2026 rates, a joint return, a hypothetical 5% state rate and selling costs inside the price. Have your CPA or attorney verify your own figures before any of this drives a decision.

Case A: a $258,000 gain in a middle bracket costs $57,104 and frees $400,896

Hypothetically you sell a rental for $700,000 with $42,000 of costs, against a $400,000 adjusted basis after $100,000 of depreciation, and you owe $200,000 on it. Realized gain is $258,000 and the equity the closing returns is $458,000. Your household has $60,000 of other taxable income.

The $100,000 depreciation layer is taxed at your ordinary rates, which are below the 25% cap here: $40,800 at 12% and $59,200 at 22%, or $17,920. The $158,000 balance sits inside the 15% band, which runs to $613,700 of joint taxable income in 2026, for $23,700. The surtax reaches only the $68,000 by which modified adjusted gross income exceeds $250,000, or $2,584.

Federal $44,204, hypothetical state $12,900, total $57,104, leaving $400,896 of cash with no deadlines attached. Exchange that equity instead and you keep $57,104 working, which is 12.5% more capital, against a 45-day identification window and the fees of whatever you buy.

Case B: a $1,750,000 gain at the top rates costs $539,000 and changes the answer

Now a $2,500,000 sale with $150,000 of costs, a $600,000 adjusted basis after $700,000 of depreciation, and a $500,000 loan. Realized gain is $1,750,000 and the closing returns $1,850,000 of equity to a household already in the top brackets.

The $700,000 depreciation layer hits the 25% ceiling for $175,000. The $1,050,000 balance is entirely above the 15% band at 20%, for $210,000. The surtax applies to the whole gain at 3.8%, or $66,500. Federal $451,500, hypothetical state $87,500, total $539,000.

That leaves $1,311,000 of cash against $1,850,000 exchanged, so the exchange starts with 41% more capital than the sale. Nothing about the property changed between the two cases; the depreciation history and the bracket did.

The exchange earns you the return on the tax you never sent, and nothing else

Hold the investment return constant across both paths and the comparison collapses to one term. If both the exchanged equity and the after-tax cash earn r a year for n years, the exchange ends ahead by the deferred tax times ((1+r) to the n, minus one), because that is the growth on money the taxable path handed to the Treasury on day one.

Case B at a hypothetical 6% for 15 years: $539,000 × (1.06^15 − 1) is about $752,700 of extra ending wealth, before exchange costs and before any sponsor load. Case A at the same 6% for 10 years is $57,104 × (1.06^10 − 1), about $45,200, which many sellers will decide is not worth reshaping a year around.

Two honest caveats belong next to that formula. It only holds if both paths really do earn the same return, so a seller who would buy something materially better with cash should model the two returns separately; and the deferred tax is still owed on a later taxable sale, which is why holding for the step-up is the other half of this decision.

Four conditions that overturn the arithmetic in either direction

The ratio is a starting point. These four facts move the answer far enough that they should be checked before any modelling.

• A large suspended passive loss argues for selling: §469(g)(1)(A) frees it entirely once the whole interest goes in a taxable sale to someone unrelated, and an exchange leaves it frozen, so the real tax on the sale can be far below the headline.
• A short life expectancy or a firm plan to hold argues for exchanging: if §1014 resets basis at death, the deferred tax is never paid, and the benefit becomes the whole $539,000 rather than the growth on it.
• A need for the money inside a few years argues for selling: exchanged equity is illiquid, and DST interests are securities with no listed exit, so the deferral can cost more in flexibility than it saves in tax.
• A thin-basis, high-leverage property argues for exchanging even on a modest gain, because the tax can approach or exceed the cash the closing returns; that case is worked through in 1031 strategies for highly leveraged owners.

Where to stop modelling, because the spreadsheet cannot settle the rest

Three inputs do not belong in the model at all. Future tax rates are unknowable, so do not build a projection that depends on them; future property returns are unknowable, so use the same assumption on both sides and let the tax be the only difference; and the quality of the replacement you can find in 45 days is a question about your pipeline, not your arithmetic.

What the model should produce is a threshold you can act on. If the tax is under roughly 15% of the equity the sale returns, treat the exchange as optional and let liquidity and simplicity decide; between 15% and 25% it is a real trade-off worth a week of work; above 25% the exchange usually wins unless you need the cash.

Breakwater Exchange works across traditional DSTs, cash out DSTs, direct title securities, bonus depreciation funds and opportunity zone funds, so a shortlist can be ready before the relinquished sale closes rather than after the clock starts.