Identify replacement within 45 days of sale; close within 180 days. Strict — no extensions.

Cash received, debt relief (old mortgage > new), personal property (furniture, equipment). Triggers immediate tax.

Carryover basis problem?

New basis is artificially low → less depreciation, larger gain when eventually sold (or stepped up at death).

When is final tax due?

When you sell without 1031-ing. Or never — heirs get stepped-up basis at death (no tax on deferred gain).

1031 Exchange Basis Calculator

New basis = old adjusted basis + boot − deferred gain. Section 1031 like-kind tax deferral.

Result

New property basis

$300,000

Realized gain $300,000; deferred $300,000; recognized $0.

Old adjusted basis$200,000
Old FMV$500,000
New FMV$600,000
Boot received$0
Realized gain$300,000
Recognized gain (taxed)$0
Deferred gain$300,000
New property basis$300,000

Step-by-step

Realized gain = old FMV − old basis = 500000 − 200000 = $300,000.
Recognized (taxed) = min(realized, boot) = $0.
Deferred = realized − recognized = $300,000.
New basis = new FMV − deferred = $300,000.

How to use this calculator

Old basis = original cost + improvements − depreciation.
Old FMV = sale price.
New FMV = replacement property cost.
Boot = any cash received.

About this calculator

Section 1031 like-kind exchanges defer capital gains tax when swapping investment real estate. Key: deferred gain becomes new property's "carryover" basis (hidden tax liability). Boot = anything received that's not like-kind property (cash, debt relief, personal property) — recognized immediately as gain. Strict 45-day identification + 180-day closing windows. Major tool for real estate investors building portfolios. Source: IRC §1031; IRS Publication 544.