United States

SALT Cap Calculator

Legal basis: IRC §164(b)(6) (limitation on the state and local tax deduction); Schedule A (Form 1040); IRC §63(c) (standard deduction) · checked 2026-10-04 · Rates and limits change — verify the current figures.

Taxpayers who itemize can deduct certain state and local taxes on Schedule A: state and local income taxes (or sales taxes, if elected instead) plus real property taxes and personal property taxes. Since 2018, IRC §164(b)(6) caps the combined deduction for these state and local taxes — the SALT cap — at a dollar limit set by law. Any state and local taxes you pay above the cap are simply disallowed as a federal deduction: they still reduce your state taxable income, but they no longer reduce your federal taxable income.

The SALT cap sits inside a bigger decision: itemizing versus the standard deduction. You itemize only when your total itemized deductions — capped SALT plus mortgage interest, charitable contributions, and a few smaller categories — exceed the standard deduction for your filing status. In high-tax states the cap is often the reason a homeowner's itemized total falls short of the standard deduction, which effectively zeroes out the federal benefit of property and state income taxes for many households.

The cap amount itself has changed by legislation. It was $10,000 from 2018 through 2024, and 2025 legislation raised it substantially with income-based phase-downs for high earners. Because the number depends on current law, this calculator makes the cap an input, along with the standard deduction and your marginal rate. Enter the current-year figures from the Schedule A instructions for your filing status.

The calculator computes your total state and local taxes, applies the cap, shows exactly how much is disallowed, totals your itemized deductions, and compares them against the standard deduction at your marginal rate to estimate the federal tax value of each path. The result is an educational estimate — not tax advice — and thresholds change annually, so confirm the figures with the IRS instructions or a CPA.

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State & local income taxes paid

State and local income tax withheld or paid. You may substitute sales tax if you elect it instead.

Real estate taxes paid

Property taxes on real estate you own, as shown on your statements.

Personal property taxes paid

Taxes on personal property like vehicles, if based on value.

Other itemized deductions

Mortgage interest, charitable gifts, and other Schedule A items (not SALT).

SALT cap

Changed by law: $10,000 for 2018–2024, raised for 2025 onward with a phase-down at high incomes — verify the current-year cap in the Schedule A instructions.

Standard deduction

Indexed annually and roughly double for joint filers — verify the current-year amount.

Federal marginal rate

The tax value of a deduction equals the deduction × this rate.

Deductible SALT (after cap)fully deductible — under the cap$16,300

Total state and local taxes paid$16,300

SALT disallowed by the capno federal deduction for this amount$0

Total itemized deductionscapped SALT + other items$30,300

Standard deduction$15,000

Better optionby $15,300 in deductionsItemize

Estimated federal tax valuebest-path deduction × 24.0% marginal rate; switching paths changes tax by $3,672$7,272

How the math works

Total SALT paid = state and local income (or sales) taxes + real property taxes + personal property taxes.
Deductible SALT = the smaller of total SALT or the cap (IRC §164(b)(6)); the excess is permanently disallowed.
Total itemized deductions = capped SALT + other itemized deductions such as mortgage interest and charity.
Compare total itemized deductions to the standard deduction; the tax value of either path is the amount × your marginal rate.

Frequently asked questions

What is the SALT deduction cap?

IRC §164(b)(6) limits the itemized deduction for the combined state and local income (or sales) taxes, real property taxes, and personal property taxes to a dollar cap set by law. Amounts paid above the cap are disallowed as a federal deduction.

How much is the SALT cap now?

It has changed repeatedly: $10,000 from 2018 through 2024, with later legislation raising it for 2025 onward and phasing it down at high income levels. Because the figure depends on current law, enter the current-year cap from the Schedule A instructions rather than relying on memory.

Does the SALT cap apply to married filing separately couples differently?

Under the original $10,000 cap, married filing separately spouses were each limited to half ($5,000). Treatment under later law follows the same structure — check the current-year instructions for your filing status.

Which taxes count toward SALT?

State and local income taxes (or, if you elect, state and local sales taxes instead — never both), real property taxes on homes or land you own, and taxes on personal property such as vehicles, to the extent based on value. Business taxes paid on Schedule C income are not subject to the cap.

Is the SALT cap ever better than no cap?

No — a cap can only reduce the deduction. But the cap interacts with the standard deduction: if your itemized total already falls below the standard deduction, the cap costs you nothing extra, because you were not going to itemize anyway.

Can I deduct state taxes paid on a business or rental?

Yes. Taxes paid in the operation of a trade or business or for the production of income — such as state income tax attributable to a Schedule C business or rental property taxes on Schedule E — are deducted on those schedules, not on Schedule A, and are not limited by the SALT cap.

What are the PTET workarounds?

Many states now offer pass-through entity tax elections: the entity itself pays the state income tax, which is a business deduction not subject to the individual SALT cap, and owners receive a credit. Rules differ by state, and the federal treatment has specific requirements.

This calculator is an educational estimate, not tax advice. The SALT cap and the standard deduction are set by legislation and change annually, and the cap can phase down at high incomes. Verify the current-year figures with the IRS Schedule A instructions or a CPA.

SALT Cap Calculator

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How the math works

Frequently asked questions

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