Reverse Estate Tax Calculator
Start with the net amount you want heirs to keep and solve backwards for the maximum gross estate that produces it. Models federal tax, state estate tax, and portability (DSUE). Especially useful near the New York cliff and other state breakpoints.
Reverse Estate Tax Calculator — Calculation Summary
| Input / parameter | Value |
|---|---|
| State | New York |
| Target after-tax amount to heirs | $10,000,000 |
| Married | Yes |
| Elect portability (DSUE) | Yes |
| Result | |
| Required gross estate | $11,270,000 |
| Estimated total tax | $1,270,000 |
| Net to heirs | $10,000,000 |
Source: Federal: IRC § 2010; State: N.Y. Tax Law § 954 (cliff: estate > 105% of exemption loses it entirely); 3-year gift lookback (2026).
This is an informal planning estimate only, not legal or tax advice. Confirm all figures with the IRS, your state Department of Revenue, or a licensed estate attorney or CPA before relying on them.
Solves backwards: given what you want heirs to keep, how large can the estate be before tax bites. For New York, watch the cliff — a gross estate just over 105% of the $7.35M exemption can trigger tax on the entire estate.
Informal estimate only — not legal or tax advice. Figures cite federal statute (IRC § 2010, OBBBA 2025) and each state's Department of Revenue. Tax laws and exemption amounts change yearly; confirm the current rule with the IRS, your state agency, or a licensed estate attorney or CPA before relying on any number.
How this calculator works
Calculation method & sources
- Federal engine: IRC § 2010(c)(3) exemption of $15M per person and IRC § 2001 graduated brackets. Portability under IRC § 2010(c)(5).
- State engine: Each state’s estate tax exemption, top rate, and special rules (such as the New York cliff) are sourced to the state’s Department of Revenue or statute.
- Reverse solver: The calculator searches for the gross estate whose combined federal + state tax leaves exactly the target net to heirs. It converges to within $1 after ~60 iterations.
How to interpret your reverse estate tax result
- “Required gross estate” is the maximum estate size that produces your target after-tax number.
- If the solver cannot find a solution, your target net may be larger than any estate in the calculator’s range.
- For New York, a small change in gross estate near the cliff can swing the tax dramatically; the result should be paired with our Safe-Zone tool.
- Portability nearly doubles the safe gross estate for married couples, but only if Form 706 is filed to elect it.