// Simplified model: assumes standard exchange expenses are handled correctly, ignores prorations, reserves, and closing-statement line items that can create small boot. Estimates only — not tax advice. Verify with your CPA and QI before closing.
Full 1031 deferral requires three things to line up: buy equal or greater in value, reinvest every dollar of equity, and replace the debt you pay off (with new debt or fresh cash). Miss any of them and the shortfall is boot — taxable, at the worst rates in your stack first. This tool runs those tests live as you type: cash boot is exchange equity that doesn't make it into the replacement; mortgage boot is debt relief not offset by new debt or added cash. Add your adjusted basis and it also caps the answer at your actual realized gain — boot can never be taxed beyond the gain that exists.
Two guides pair with this tool: What Is Boot explains every way it sneaks in (including the closing-statement line items this simplified model ignores), and The Tax Math turns a boot number into an actual dollars-owed estimate across all four tax layers.
No boot detected means the structure passes as entered — which is the beginning of diligence, not the end; settlement statements create small boot in ways no calculator sees in advance. Boot detected is not a failure: every line in the breakdown is fixable before closing (a DST for the cash remainder, a bigger loan, added cash), or it's a number you can choose to take deliberately and pay tax on — the point is choosing. Numbers don't close means the purchase as described can't be funded from the equity and cash entered; something has to move.
Run this before you go under contract, not after. Every boot surprise we've autopsied traces to exchange math done last instead of first — usually the mortgage line. Ninety seconds here, weeks before closing, is the cheapest tax planning in the entire process.
A free, no-obligation introduction to a vetted 1031 or DST partner — with our referral relationship disclosed in writing. On the 45-day clock? Same-day attention.