Mortgage Tax Savings Calculator
If you itemize, mortgage interest is deductible. Estimate the first-year tax savings and your effective after-tax interest rate.
Free to use No sign-up needed Updates as you type
Default interest rate: 7.18% — Freddie Mac 30-year fixed average, week of Nov 5, 2026. Enter the rate from your own Loan Estimate.
How the mortgage tax savings calculator works
Owning a home can lower your federal tax bill, but only if your deductible housing costs are large enough to beat the standard deduction — and this calculator does that comparison honestly. It adds your annual mortgage interest and deductible property tax to your other itemized deductions, then checks whether the total tops the standard deduction for your filing status.
Only the amount above that threshold is genuinely new deduction, and your tax savings is that excess multiplied by your marginal tax rate. The result is the real, incremental benefit, not the inflated number you'd get by deducting from zero.
Worked example: with loan amount of $300,000, interest rate of 7.18% and loan term (years) of 30, the mortgage tax savings calculator shows first-year tax savings of $5,147.
- First-year interest
- $21,444
- Tax savings
- $5,147
- After-tax interest rate
- 5.46%
- Monthly tax benefit
- $428.89
| Loan amount | First-year tax savings |
|---|---|
| $150,000 | $2,573 |
| $300,000 | $5,147 |
| $500,000 | $8,578 |
| $750,000 | $12,867 |
The formula
Itemized total = mortgage interest + deductible property tax + other itemized deductions. Incremental deduction = max(0, itemized total − standard deduction). Estimated tax savings = incremental deduction × marginal tax rate. If itemized total is below the standard deduction, the mortgage produces no extra federal tax benefit.
How every calculator here computes, what it assumes and how the defaults stay current: our methodology.
- Property-tax deductions fall under the SALT cap, which limits combined state and local taxes you can write off.
- Mortgage interest is deductible only on acquisition debt up to the IRS principal limit; balances above it deduct partially.
- Benefit applies to federal income tax; state treatment varies and is not modeled here.
- Uses a single marginal rate, but deductions can span tax brackets, so the true saving may differ modestly from the estimate.
- This is an estimate, not tax advice — confirm your situation with a tax professional before relying on the figure.
Reference data
Current figures behind this tool: Mortgage Credit Certificate (MCC), First-Time Home Buyer Tax Credit.
Results are estimates for educational purposes and are not financial advice. Confirm exact figures with your lender or a licensed advisor.
Questions about the mortgage tax savings calculator
Why might my mortgage produce no tax savings at all?
Because the deduction only helps if itemizing beats the standard deduction, which is generously high. If your interest, capped property tax, and other write-offs together fall short of the standard amount, you'd take the standard deduction anyway — and the mortgage adds nothing extra. Many homeowners, especially later in a loan, land in exactly this position.
How does my tax bracket change the size of the benefit?
Your savings equals the deductible amount multiplied by your marginal rate, so a higher bracket means a larger benefit per dollar deducted.
The same $10,000 of deductible interest saves far more for someone in a top bracket than for someone in a low one. The deduction's value scales directly with the rate it offsets.
What is the SALT cap and how does it affect this?
The SALT cap limits the total state and local taxes — including property tax — you may deduct in a year.
If your property and state income taxes exceed that limit, the excess can't be written off, which trims the property-tax portion of your itemized total and can be the difference between itemizing and taking the standard deduction.
Is my information saved or shared?
No. Every calculation runs entirely in your browser. We never store, transmit or sell the numbers you enter.
Can I deduct my mortgage interest?
If you itemize, you can generally deduct interest on up to $750,000 of mortgage debt, plus property taxes within the SALT cap. It only helps if your itemized total beats the standard deduction — estimate your savings above.
Sources
- IRS — Publication 936, Home Mortgage Interest Deduction
- IRS — Publication 530, Tax Information for Homeowners
- Freddie Mac — Primary Mortgage Market Survey (weekly average rates)
- CFPB — Loan Estimate explainer
How the figures on this site are calculated and tested: methodology · editorial policy.
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