Washington Estate Tax Calculator
Last updated: 24 Oct 2025 • Author: Alexander Foelsche CPA (US), WP (DE), RE (CH)
Washington Estate Tax — Calculator
Interactive estimator for Washington’s Estate & Transfer Tax (DoD on/after July 1, 2025, exclusion $3,000,000). Models resident vs. nonresident apportionment, basic deductions, and optional QFOBI/Farm. Get help with your WA return
Washington Estate Tax — Quick Calculator (DoD ≥ 7/1/2025)
Calculates instantly as you type. Real cases (QTIP elections, QFOBI/Farm tests, entity situs, alternate valuation) may differ.
1) Decedent & estate
2) Deductions & elections
3) Results
WA-situs base (apportionment numerator)
$0
Pre-apportioned taxable estate
$0
Tentative tax (before apportionment)
$0
Apportionment factor
0.0000
WA estate tax (apportioned)
$0
Effective rate on WA-situs base
0.00%
Filing-threshold test (DoD ≥ 7/1/2025): Adjusted gross for filing = Worldwide gross estate − decedent’s share of the personal residence. Compare to $3,000,000.
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Need a formal computation and filing? Washington Estate Tax Service
How to use the calculator
1) Pick residency
Resident includes intangibles in the numerator (subtract out-of-state real/tangibles). Non-resident uses only WA-situs real/tangible assets.
2) Enter the worldwide gross estate
Use federal Form 706 schedules as scaffolding. For nonresidents, this is still the worldwide gross estate; the fraction limits tax to WA.
3) Add deductions
Debts & administration, marital and charitable reduce the base. Optionally include QFOBI (cap $3,000,000) and Farm if eligible.
4) Filing threshold check
Enter the decedent’s share of the personal residence to run the DOR filing-threshold test for DoD ≥ 7/1/2025 vs. the $3,000,000 exclusion.
5) Read the outputs
See pre-apportioned taxable estate and tentative tax, then the apportionment factor and effective rate. For formal filings, use DOR tables and addenda.
Tips & limitations
- Teaching estimator. The return requires DOR schedules, Addendum #4, and documentation (appraisals, court-approved fees, election statements).
- No state portability. Consider a state-sized bypass or WA QTIP in planning; test spousal/charitable allocations here.
- QFOBI/Farm have strict eligibility. Enter only defensible amounts; keep affidavits and financials.
- If you’ll extend to file, make a tentative payment by month 9 to limit interest.
Not legal or tax advice. Always follow the current DOR instructions for the date of death.