1031 Exchange Deadline Calculator (45/180 Days)
Calculate exact statutory 45-day identification and 180-day closing deadlines for IRS Section 1031 like-kind property exchanges. Includes weekend rules and boot tax.
Interactive WebAssembly Calculation Engine
This tool runs 100% in your local web browser tab. All amortization schedules, debt yield calculations, and tax deferral projections are computed client-side in WebAssembly. Zero bytes are uploaded to remote servers.
Use the interactive form above to adjust parameters, toggle extra principal schedules, stress-test interest rates, and export full reports to Excel (.xlsx) or CSV.
Underwriting Methodology & Mathematical Formulation
Our calculation algorithms strictly adhere to institutional lending conventions, CFPB disclosure rules, and statutory IRS definitions:
- Standard Annuity Formula: Monthly payment M = P * [r(1+r)^n] / [(1+r)^n - 1], calculating exact interest and principal allocations down to the penny.
- Zero-Roundoff Double Precision: Computations execute using standard IEEE 754 floating-point and integer math to match commercial bank loan documents.
- Sensitivity Analysis: Real-time stress testing against interest rate fluctuations, vacancy rate increases, and balloon maturity horizons.
Frequently Asked Questions
What are the strict 45-day and 180-day deadlines in an IRS Section 1031 exchange?
Under IRC §1031, you have exactly 45 calendar days from closing on your relinquished property to identify potential replacement properties in writing, and exactly 180 calendar days (or your tax return due date, whichever is earlier) to acquire the replacement property.
Can the 45-day or 180-day deadlines be extended if they land on a weekend or holiday?
No. IRS regulations strictly enforce calendar days. If day 45 or day 180 falls on a Saturday, Sunday, or federal holiday, the deadline does NOT roll over to the next business day. Missing the deadline by even one day disqualifies the entire exchange.
How do I avoid taxable boot during a like-kind exchange?
To achieve 100% tax deferral, you must reinvest all net cash proceeds and acquire replacement property of equal or greater value and debt. Any net cash withheld or mortgage debt reduction not offset by fresh capital is considered taxable boot.