Mortgage Interest Deduction Calculator
Mortgage Interest Deduction Calculator
Other Itemized Deductions
The mortgage adds $13,402 of deductions beyond what you would claim without it, taxed at a combined 24% rate.
Based on your results — what to do next:
See the full payment picture
You pay about $29,102 in interest this year and save roughly $3,216 in tax. Check the payment and payoff schedule.
Estimate your full tax bill
With $45,602 in deductions, run the whole return through the federal and state brackets.
Would refinancing help?
At 6.5% your $29,102 of yearly interest is only partly offset by a $3,216 tax break. Compare a lower rate.
The mortgage interest deduction lets you deduct interest on up to $750,000 of home acquisition debt, but only if you itemize and your itemized total beats the standard deduction. This calculator computes your interest for the year, adds property and state taxes up to the SALT cap, compares the total to the 2026 standard deduction, and estimates what the mortgage actually saves you in tax.
How the Mortgage Interest Deduction Works
① Interest paid in the year
Interest = Σ (Balance × APR ÷ 12) over the 12 payments
Early loan years are interest-heavy because the balance is highest.
② Itemized total
Itemized = Deductible Interest + min(Property Tax + State Tax, SALT Cap) + Charity + Other
Interest is scaled down by $750,000 ÷ balance when the loan exceeds the limit.
③ Benefit of the mortgage
Extra Deduction = max(Standard, Itemized) − max(Standard, Itemized without mortgage interest); Savings = Extra × (Federal + State Rate)
This isolates what the mortgage adds, not the full itemized amount.
| Variable | Meaning | Typical Value |
|---|---|---|
| Standard deduction (2026) | Single $16,100 · Married filing jointly $32,200 · Head of household $24,150 | Adjusted for inflation each year |
| SALT cap | State and local tax deduction limit | $40,400 for 2026, phasing down for high incomes (not modeled here) |
| Debt limit | Acquisition debt eligible for interest deduction | $750,000 ($375,000 if married filing separately) |
| Marginal rate | Tax rate on your last dollar of income | 10%–37% federal |
Worked Example — married filing jointly, $450,000 loan at 6.5% for 30 years, year 1
- Interest paid in year one ≈ $29,102
- Property tax $6,500 + state tax $7,000 = $13,500 (under the SALT cap); charity $3,000
- Itemized total = $29,102 + $13,500 + $3,000 = $45,602 vs. a $32,200 standard deduction
- Without the mortgage, itemized would be $16,500, so you would take the $32,200 standard deduction
- Extra deduction = $45,602 − $32,200 = $13,402 → at 24% federal, savings ≈ $3,216
💡 Pro-Tip
The deduction is smaller than most people think.Because the standard deduction is so large, many homeowners get no tax benefit at all from mortgage interest. Only the amount by which your itemized total exceeds the standard deduction saves you money, and then only at your marginal rate. Do not justify a bigger loan or a longer term because "the interest is deductible": you still pay $1 of interest to save at most 37 cents.
Mortgage Interest Deduction Calculator FAQ
Is mortgage interest still tax deductible in 2026?
Yes, if you itemize. Interest on up to $750,000 of acquisition debt on a primary or second home is deductible, but it only helps if your itemized deductions exceed the standard deduction.
What is the standard deduction in 2026?
For 2026 it is $16,100 for single filers, $32,200 for married filing jointly, and $24,150 for head of household. Confirm current figures with the IRS before filing.
Does the mortgage interest deduction apply to home equity loans?
Only if the funds were used to buy, build, or substantially improve the home that secures the loan. Interest on home equity debt used for other purposes is not deductible.
How much will the mortgage interest deduction save me?
Multiply the amount your itemized deductions exceed the standard deduction by your marginal tax rate. In the example above, a $13,402 extra deduction at 24% saves about $3,216 a year.