How Estate Tax Calculator Works
The Estate Tax Calculator estimates federal estate tax liability and helps you understand how various planning strategies can reduce or eliminate the tax burden on your estate. It models the current federal estate tax framework including the unified credit, applicable exemption amounts, and graduated tax rates up to 40%.
The calculator begins by computing your gross estate — the total fair market value of everything you own at death, including real estate, investments, retirement accounts, life insurance death benefits, business interests, and personal property. It then subtracts allowable deductions: debts and mortgages, funeral expenses, administrative costs, charitable bequests, and the unlimited marital deduction for assets passing to a surviving U.S. citizen spouse.
The resulting taxable estate is compared against the federal estate tax exemption (currently $13.61 million per individual for 2024, scheduled to revert to approximately $7 million in 2026 unless Congress acts). Only the amount exceeding the exemption is subject to the 40% federal estate tax rate. The tool also models portability — the ability for a surviving spouse to use their deceased spouse's unused exemption, effectively doubling the exemption for married couples who properly elect it.
Beyond the basic calculation, the tool models common estate planning strategies including irrevocable life insurance trusts (ILITs), grantor retained annuity trusts (GRATs), qualified personal residence trusts (QPRTs), and annual gift exclusion programs. Each strategy shows the estimated estate tax savings and implementation considerations. Pair this with the Monte Carlo Retirement Simulator simulator to ensure estate planning does not compromise retirement security, or the 1031 Exchange Calculator for real estate within the estate.
Key Terms Explained
- Federal Estate Tax Exemption
- The amount of a decedent's estate that passes free of federal estate tax. Currently $13.61 million per person, scheduled to decrease to approximately $7 million after 2025.
- Unlimited Marital Deduction
- A provision allowing unlimited asset transfers to a surviving U.S. citizen spouse free of estate tax, effectively deferring tax until the second spouse's death.
- Portability
- The ability of a surviving spouse to add their deceased spouse's unused estate tax exemption to their own, but only if a timely estate tax return is filed electing portability.
- Irrevocable Life Insurance Trust (ILIT)
- A trust that owns life insurance policies outside the insured's estate, preventing the death benefit from being subject to estate tax while providing liquidity to pay estate taxes or equalize inheritances.
- Step-Up in Basis
- The adjustment of an inherited asset's cost basis to its fair market value at the decedent's date of death, eliminating capital gains tax on appreciation during the decedent's lifetime.
- Unified Credit
- The tax credit that effectively exempts a certain amount of estate value from taxation, corresponding to the applicable exclusion amount.
Who Needs This Tool
Estimating their estate tax exposure with a $25 million estate and modeling how gifting $5 million to an irrevocable trust today could save over $2 million in future estate taxes.
Determining whether to elect portability on a recently deceased spouse's estate return to preserve their unused $13.61 million exemption for future use.
Illustrating to clients how the scheduled 2026 exemption sunset will increase their estate tax bill and building urgency for implementing planning strategies now.
Modeling estate tax liability on a closely-held business valued at $15 million and exploring installment payment options under IRC Section 6166.
Running estate projections for a couple aged 65 to show how their growing investment portfolio could create an estate tax problem within 15-20 years even though they are below the exemption today.
Methodology & Formulas
Gross estate is the sum of all asset values at fair market value on the date of death (or alternate valuation date if elected). Taxable estate equals gross estate minus deductions (marital, charitable, debts, expenses). The tentative tax is calculated using the unified rate schedule (18% on the first $10,000 up to 40% on amounts over $1 million). The applicable credit amount (unified credit) offsets tax dollar-for-dollar up to the exemption equivalent. Net estate tax equals tentative tax minus unified credit minus any state death tax credit.
Pro Tips
- Even if your estate is below the current exemption, model the 2026 sunset scenario — estates between $7-13.6 million face a potential $2.6 million tax increase if the exemption reverts.
- Always file Form 706 to elect portability when the first spouse dies, even if no tax is owed. Failing to elect is irrevocable and could cost the surviving spouse millions.
- Life insurance proceeds are included in your gross estate if you own the policy. Transfer ownership to an ILIT at least 3 years before death to exclude it.
- Remember that state estate taxes have much lower exemptions — many states tax estates above $1-5 million, creating liability even when federal exemption protects you.
- The step-up in basis at death can be more valuable than avoiding estate tax. In some cases, it is better to hold appreciated assets until death rather than gifting them during life.