Free planning tool · 2026

Illinois Estate Tax Calculator

Estimate your Illinois estate tax exposure. Then explore the questions and planning choices behind the number.

Enter the estate’s value after subtracting allowable debts, expenses, and other deductions. The calculator handles the Illinois estate-tax deduction automatically—do not subtract that tax yourself. Need help adding up assets and deductions? Open the “Optional estate worksheet” directly below.

Optional estate worksheet — add assets and deductions

Use this worksheet for a straightforward estate. Include each asset once. Blank worksheet fields count as $0. Estimates are only as complete as the information you enter.

This worksheet does not determine ownership, deductibility, valuation discounts, or Illinois QTIP adjustments. If those issues apply, use a professionally prepared Form 700 figure in the main field below.

1. Add includible assets

Home and other real estate

Use the includible ownership share at market value, before mortgages.

Cash and taxable investment accounts

Include trust-owned and jointly owned amounts only to the extent includible.

Retirement accounts

Include applicable IRA, 401(k), and other retirement benefits.

Business and farm interests

Use an estimated includible value; specialized valuation may be needed.

Includible life insurance proceeds

Use the death benefit if includible—not simply the policy cash value.

Other includible property

Include personal property and other interests not counted above.

2. Subtract allowable deductions

Allowable debts and expenses

Include allowable mortgages, other debts, and estate-administration expenses. Reasonable attorney and accountant fees for administering the estate may be deductible. Count each expense once; exclude the Illinois estate tax calculated here.

For planning, estimate attorney fees at 2–3% of the estate’s value before deductions. CPA fees vary by filing. Actual fees and deductibility depend on the estate.

Qualifying marital deduction

Not every transfer to a spouse or trust qualifies. Confirm eligibility first.

Qualifying charitable deduction

Include only deductible transfers to qualifying recipients.

Do not subtract lifetime gifts here. Enter adjusted taxable gifts separately below. Changing this worksheet does not update the main amount until you select the button.

Illinois tentative taxable estate

For a prepared return, use Form 700, Schedule A or B, line 3. Include required Illinois QTIP adjustments. Do not deduct the $4 million exclusion or the estimated state estate tax from this input.

Adjusted taxable gifts (after 1976)

Use Form 700, Schedule A or B, line 4—not all lifetime gifts and not line 5. Leave $0 only if none. If unknown, confirm your gift-tax records before relying on the estimate.

No email required. The calculation runs in your browser.

A.H.Steinmetz, Ltd. · Illinois estate planning

Illinois estate tax planning estimate

Illinois tentative taxable estate
Adjusted taxable gifts
Estimated Illinois estate tax

What this estimate assumes

Illinois resident; all property has Illinois tax situs; 2026 law. The estate input is after allowable deductions and applicable Illinois QTIP adjustments, but before the Illinois estate tax deduction. The calculator does not determine whether deductions or valuations are legally available.

No out-of-state apportionment, federal estate tax, penalties, or interest is included. Prior gifts can affect tax. A zero estimate does not establish that no return is required. This is general information, not a tax return or individualized legal advice.

Prepare for a conversation

Gather an asset list, ownership details, existing estate-planning documents, and any gift-tax returns. Confirm uncertain values and deductions with your advisers.

Discuss your estate tax exposure: (618) 281-7618
https://steinmetzltd.com/schedule-consultation/

Calculator: https://steinmetzltd.com/illinois-estate-tax-calculator/
Official forms and calculation: https://illinoisattorneygeneral.gov/estate-taxes/

Start with the right figures

Two inputs. One estimate.

Tentative taxable estate

The estate’s value after allowable debts, expenses, and other deductions. The calculator handles the Illinois estate-tax deduction for you. Property outside probate may still count. Open the “Optional estate worksheet” above the estate input if you need help adding up assets and deductions.

Adjusted taxable gifts

The relevant taxable gifts already made during life. Enter gifts separately from the estate, and do not subtract them again from an estate figure that already excludes them.

Help with estate assets and deductions
Help identifying earlier taxable gifts

Scope of this estimate

Illinois resident; all property has Illinois tax situs. Illinois estate tax only. Out-of-state allocation, federal tax, and QTIP elections require separate analysis.

Understand your result

A starting point for planning

The estimate reflects the amounts you entered. It does not decide which assets belong in the estate or whether a deduction qualifies. A $0 estimate is not a determination that no return is required.

Why the $4 million threshold is not a simple deduction

Illinois uses an interrelated calculation. The state estate-tax deduction affects the computation, and adjusted taxable gifts enter part of it. Do not subtract the exclusion or the estimated state tax yourself. See examples at different estate values.

What if I am married or own property outside Illinois?

The calculator estimates one estate. Illinois does not automatically transfer an unused exclusion to a surviving spouse. Marital and QTIP planning needs to address both deaths. For property outside Illinois, this result is preliminary and may require apportionment.

What belongs in the optional worksheet?

Include the applicable shares of real estate, investments, retirement benefits, business interests, trust property, and life insurance. Avoid counting assets twice. Enter real estate before subtracting an allowable mortgage under deductions. For includible life insurance, use the death benefit. Review the asset guide when ownership or deductions are uncertain.

Sources and calculation method

The estimator uses the former federal state death tax credit and Illinois’s hypothetical federal-tax limitation, accounting for the interrelated state estate-tax deduction. Checks against published examples allow for small differences from whole-dollar rounding. It is not an official government calculator.

Explore a planning option

How lifetime gifting could change your estate tax

For example, consider an estate worth $4.8 million. The comparison shows how making a lifetime gift could reduce Illinois estate tax compared with keeping the assets until death.

The overall benefit also depends on the property’s basis and the assets you need to retain.

Explore lifetime gifting →

Carry your entered figures into the explorer. If you have not entered an estate, its inputs start at $0.

Two paths for the same starting estate

Keep $4.8 million until deathNo adjusted taxable gifts: $228,571Illinois estate tax
Give $2.8 million; retain $2 million$2.8 million in adjusted taxable gifts: $92,910Illinois estate tax

$135,661 less Illinois estate tax

Same asset values and deductions; no earlier gifts, growth, or spending. Completed taxable gift excluded from the estate at death; all property has Illinois tax situs. Figures exclude any income-tax cost from losing a basis adjustment.

Choose your next question

Understand the details that matter to you

What numbers should I enter?

Identify the assets, deductions, and earlier gifts behind your estimate.

Why does the result look like this?

Understand the calculation and the difference between state and federal tax.

What could change my situation?

Explore planning choices and circumstances that need a closer look.