How Our Numbers Work: Every Assumption, Sourced
The tax rates, deadline rules, and formulas inside every 1031 Deferred calculator — cited to the Code, with a change log. Check our math.
Every calculator on this site runs on parameters you can check. This page lists each one, its source, and when it was last reviewed. If a figure here disagrees with your CPA, trust your CPA — these are educational defaults, not advice.
Tax parameters (tax year 2026)
| Federal long-term capital gains rates | 0% / 15% / 20% by bracket | IRC §1(h) |
| Unrecaptured §1250 gain (depreciation recapture) | capped at 25% | IRC §1(h)(1)(E), §1250 |
| Net investment income tax | 3.8% above MAGI thresholds | IRC §1411 |
| State rate presets | TX/FL/NV 0% · CO 4.4% · PA 3.07% · NY 10.9% · CA 13.3% | top marginal state rates; see the 50-state table |
Deadline rules
The 45-day identification and 180-day exchange periods run in calendar days from the transfer of the relinquished property, with no extension for weekends or holidays — IRC §1031(a)(3); Treas. Reg. §1.1031(k)-1(b). The exchange period ends at the earlier of 180 days or the due date of the taxpayer's return for the year of transfer, which is why late-year closings usually require filing an extension — §1031(a)(3)(B). Disaster-relief extensions under Rev. Proc. 2018-58 can modify these dates; the calculator flags the rule but cannot know your county.
How the tax-deferred number is computed
Adjusted basis = purchase price + capital improvements − accumulated depreciation. Amount realized = sale price − selling costs. Total gain = amount realized − adjusted basis. Recapture gain = the lesser of accumulated depreciation and total gain, taxed at 25%; remaining gain at the selected LTCG rate; NIIT applied to the whole gain when toggled; state rate applied to the whole gain. This mirrors the ordering a preparer uses on Schedule D and Form 4797 at the level of precision an educational estimate supports.
What the calculators deliberately do not do
No projections of any specific investment's returns, no offering terms, no fees of any live product. DST-related assumptions are user-entered or shown as illustrative ranges only.
Change log
- July 2026 — initial publication; TY2026 parameters; deadline logic v1; state preset rates verified against top marginal rates.
Annual review each January: LTCG brackets, NIIT threshold, state rates, accreditation dollar tests.