Your SALT Deduction Results
Salt Cap Relief 40000 Threshold Phaseout Calculator
What This Calculator Does and Why It Matters
The federal SALT (State and Local Tax) deduction has been capped at $10,000 since the 2017 Tax Cuts and Jobs Act. Proposed legislation would raise this cap to $40,000 — but not for everyone. Higher-income taxpayers face a phaseout that reduces their cap once their Modified Adjusted Gross Income (MAGI) exceeds $500,000.
This free calculator helps you find your effective SALT deduction cap under the proposed relief rules, estimate your actual allowable deduction, and calculate your federal tax savings based on your marginal rate. If you live in a high-tax state like California, New York, or New Jersey, this number can make a significant difference in your annual tax bill.
For a broader look at how deductions interact with your federal return, the IRS Topic 503 page on deductible taxes is a helpful reference.
How to Use This Calculator
Step-by-Step Instructions
- Select your filing status — Single, Married Filing Jointly, or Head of Household.
- Enter your Modified Adjusted Gross Income (MAGI) for the tax year.
- Enter the total SALT you paid — this includes state income tax or sales tax plus local property taxes combined.
- Enter your federal marginal tax rate as a percentage (for example, 32 or 35).
- Click Calculate to see your phaseout reduction, effective cap, allowable deduction, and estimated tax savings.
- Click Reset to clear all fields and start over.
If you’re also evaluating other deductions this season, the QBI Deduction Calculator can help you see how pass-through income deductions work alongside SALT.
The Formula Explained
Breaking Down the Formula
The proposed SALT relief works as follows. The base cap is raised to $40,000. For taxpayers with MAGI above $500,000, the cap is reduced dollar-for-dollar until it reaches the old floor of $10,000. Once MAGI exceeds $530,000 (for most filers), the cap is fully phased out back to $10,000.
The core formula steps are: Phaseout Reduction = min(MAGI − $500,000, $30,000). Then: Effective Cap = $40,000 − Phaseout Reduction. The allowable deduction is the lesser of your SALT paid or your Effective Cap. Tax savings = Allowable Deduction × Marginal Rate.
Example Calculation with Real Numbers
Suppose you are married filing jointly with a MAGI of $510,000. You paid $22,000 in property and state income taxes combined. Your marginal tax rate is 35%.
Phaseout reduction = $510,000 − $500,000 = $10,000. Effective cap = $40,000 − $10,000 = $30,000. Since your SALT paid ($22,000) is less than $30,000, the full $22,000 is deductible. Your estimated federal tax savings = $22,000 × 35% = $7,700.
You can also use the Section 179 Depreciation Deduction Calculator if you’re a business owner looking to pair deductions strategically in the same tax year.
When Would You Use This
Real Life Use Cases
This calculator is most useful during tax planning, not just at filing time. Knowing your effective SALT cap in advance lets you make better decisions about estimated payments, itemized deductions, and whether itemizing makes sense at all versus taking the standard deduction.
Homeowners in high-property-tax states benefit most. A family in Westchester, New York, might pay $20,000 or more in property taxes alone. Combined with state income tax, their total SALT can easily exceed the old $10,000 cap by a wide margin. The new $40,000 limit would offer them real and substantial relief — as long as their income stays below the phaseout threshold.
Specific example scenario
A self-employed consultant in New Jersey has MAGI of $485,000 and pays $18,000 in property taxes and $9,000 in state income taxes — a combined SALT of $27,000. Under the old rules, she can only deduct $10,000. Under the proposed $40,000 cap, she deducts the full $27,000. At a 35% marginal rate, that’s an additional $5,950 in tax savings over the old cap.
Tips for Getting Accurate Results
Use MAGI, Not Regular AGI
MAGI (Modified Adjusted Gross Income) can differ from your standard AGI when you add back certain deductions like student loan interest or IRA contributions. Use the correct MAGI figure to get a precise phaseout result. Your prior-year tax return is often the fastest way to find it.
Combine All SALT Components
SALT includes state income tax (or state sales tax if you elect that), plus local real estate taxes. Do not include federal income taxes or foreign taxes — those do not count. Also note that personal property taxes on vehicles do count if assessed on value.
Verify the Bill Status Before Filing
This calculator is based on proposed legislative changes. The $40,000 cap is not yet permanently enacted law. Always confirm the current SALT rules with your tax preparer or check the official Congress.gov bill tracker before making filing decisions based on any proposed changes.
Frequently Asked Questions
What is the SALT deduction?
SALT stands for State and Local Taxes. It allows taxpayers who itemize their federal deductions to deduct the state income or sales taxes they paid, plus local property taxes. Since 2018, the deduction has been capped at $10,000 per return.
What is the proposed $40,000 SALT cap?
Legislation has been proposed to raise the SALT deduction cap from $10,000 to $40,000 for most taxpayers. This would primarily benefit homeowners in high-tax states who pay significant property and state income taxes each year.
Who is affected by the phaseout?
Taxpayers with MAGI above $500,000 see their $40,000 cap reduced dollar-for-dollar. Once MAGI reaches $530,000 or above (for most filing statuses), the cap is fully phased out back to the $10,000 floor.
Does the cap change for married filing jointly?
Under current law, married couples filing jointly face the same $10,000 cap as single filers — which many consider a marriage penalty. The proposed $40,000 cap applies equally to joint filers, though the phaseout threshold remains $500,000 regardless of filing status.
Can I deduct both property taxes and state income taxes?
Yes. The SALT deduction is a combined total of state and local income taxes (or state sales taxes, whichever you elect) and real estate property taxes. The cap applies to the combined total, not to each category separately.
What if my SALT paid is less than the cap?
You can only deduct what you actually paid. If your total SALT is $12,000 and your effective cap is $40,000, you still only deduct $12,000. The cap sets the maximum — it does not guarantee that amount as a deduction.
Is the $40,000 SALT cap already law?
As of mid-2025, the $40,000 cap is a proposed change being debated in Congress. It has not been permanently enacted. Always verify current law with a qualified tax professional or IRS resources before using it in your actual return.
How does SALT interact with the Alternative Minimum Tax?
The AMT does not allow the SALT deduction at all. High-income taxpayers subject to AMT may not benefit from SALT relief even if the cap is raised. If you are near the AMT threshold, run an AMT calculation alongside your regular tax to see which applies. You might also find the Estimated Quarterly Tax Payment Calculator useful for planning.
Conclusion
The proposed SALT relief — raising the deduction cap to $40,000 with an income-based phaseout starting at $500,000 — would be meaningful relief for millions of homeowners in high-tax states. But the phaseout means your actual benefit depends heavily on your MAGI.
Use this calculator to model your specific situation before tax season, and pair it with a full review of all itemized deductions to decide whether itemizing beats the standard deduction in your case. Tax planning done early almost always saves more than tax planning done at the last minute.