Free mortgage tax savings calculator
Estimate your annual mortgage interest deduction tax savings — enter interest paid, tax bracket, and standard deduction to see the net benefit, updated live, as you type.
On this page10 sections
Requires itemizing deductions. Only beneficial if itemized deductions exceed the standard deduction ($30,000 for MFJ 2024). Consult a tax advisor.
Results are estimates. Consult a professional.
How the mortgage tax savings calculator works
US homeowners who itemize deductions can deduct the mortgage interest they pay from their taxable income. The calculator estimates how much that deduction is worth in actual tax dollars, based on your loan, rate, and marginal tax bracket. The higher your bracket, the more valuable each dollar of deductible interest becomes.
Worked example: $400,000 at 7%, two tax brackets
A homeowner carries a $400,000 mortgage at 7%. In year 1, their interest charges sum to approximately $27,677. How much does itemizing save at two different tax brackets?
Annual tax savings by loan size and tax bracket
The table shows estimated year-1 federal tax savings for common loan sizes at 7%, across the four most common marginal brackets. These are gross savings before comparing to the standard deduction. Actual benefit depends on your total itemized deductions.
| Loan amount | 22% bracket | 24% bracket | 32% bracket | 37% bracket |
|---|---|---|---|---|
| $200,000 | $3,051 | $3,329 | $4,438 | $5,131 |
| $300,000 | $4,576 | $4,992 | $6,657 | $7,693 |
| $400,000 | $6,089 | $6,643 | $8,857 | $10,241 |
| $500,000 | $7,614 | $8,306 | $11,071 | $12,799 |
Source: IRS Publication 936; Tax Cuts and Jobs Act 2017 ($750k cap). Assumes 7% rate, year-1 interest, full itemization benefit. State income tax deductions may add further savings.
Loans above $750,000 are partially capped: only the interest attributable to the first $750,000 of principal is deductible. The deduction also phases out as the loan balance shrinks over the years.
Tips for maximizing your mortgage interest deduction
The mortgage interest deduction is valuable only if you itemize — and only for the portion of your itemized total that exceeds the standard deduction. Here is how to think about it clearly.
- First check whether itemizing beats the standard deduction — add up mortgage interest, property taxes (capped at $10,000 SALT), charitable contributions, and other deductible items. If the total is less than your standard deduction, itemizing adds no benefit.
- Your tax savings decline each year automatically — as you pay down the mortgage, the balance and monthly interest shrink. A calculator showing year-1 savings overstates the long-run average. Year-10 savings on a $400k loan at 7% are roughly $5,200, not $6,089.
- Only the first $750k qualifies post-2017 — if your loan exceeds $750,000, the deductible interest is prorated: multiply your total interest by $750k ÷ loan_amount.
- Second-home mortgages also qualify — interest on a second home is deductible within the same $750k combined limit (first + second mortgage). Rental property interest is deducted differently — as a business expense on Schedule E, not as personal mortgage interest.
- Points paid on purchase are deductible in the year paid — if you bought discount points, those count as prepaid mortgage interest and are fully deductible in the year of purchase when you itemize.
Accuracy and limitations
Tax savings estimates are based on federal marginal rates only and assume you itemize deductions in full. The SALT (state and local tax) deduction cap of $10,000 per household, the Alternative Minimum Tax (AMT), and phase-outs for high-income filers can reduce or eliminate the actual benefit. State income tax savings — which compound the federal benefit for taxpayers in high-rate states — are not included. The $750,000 loan cap and the $1,000,000 grandfathered cap for pre-2018 loans are applied based on your loan amount input.
Not financial advice — consult a mortgage professional for your specific situation.
Mortgage tax terms defined
About this mortgage tax savings calculator
This calculator runs entirely in your browser — nothing you enter is sent to any server.
Browse more in our finance calculators, or explore the complete library on the free calculators page.