Mortgage Interest Deduction Calculator
Calculate your mortgage interest deduction and find out whether itemizing or taking the standard deduction saves you more on taxes in 2026.
Mortgage Details
Other Itemized Deductions
Itemizing Saves You More
$36,000
total itemized deductions
Extra Savings from Itemizing:
$4,378
$19,900 above standard deduction x 22% marginal rate
Deduction Breakdown
Mortgage under $750,000 limit
Itemized vs Standard Deduction
Itemized
$36,000
Tax savings: $7,920
Better Choice
Standard
$16,100
Tax savings: $3,542
Estimated Tax Savings
At your marginal tax rate of 22%, your total deduction of $36,000 saves you approximately $7,920 in federal income taxes.
Important Note
The TCJA limited the mortgage interest deduction to $750,000 of acquisition debt for loans after December 15, 2017. The SALT deduction is capped at $10,000 ($5,000 for married filing separately). These limits are current through 2026.
Understanding the Mortgage Interest Deduction
$750K Mortgage Limit
For loans originated after December 15, 2017, you can deduct interest on up to $750,000 of mortgage debt ($375,000 for married filing separately). Pre-TCJA loans keep the $1M limit.
SALT Cap ($10K)
State and local taxes (property tax + state income/sales tax) are capped at $10,000 total. This significantly limits deductions in high-tax states.
Points Deduction
Mortgage points (origination fees) paid at closing are generally deductible in the year paid for a purchase, or amortized over the loan term for a refinance.
Special Rules for Self-Employed Homeowners
Home Office Deduction
Self-employed individuals can deduct a portion of mortgage interest as a business expense through the home office deduction. This is separate from Schedule A itemized deductions.
No Double-Dipping
The portion of mortgage interest claimed as a home office deduction on Schedule C cannot also be claimed on Schedule A. Split your interest accordingly.
Rental Property
Mortgage interest on rental properties is deductible on Schedule E, not Schedule A. There is no $750K limit on rental property mortgage interest.
Official References
This calculator uses current IRS rules for mortgage interest deductions:
- IRS Publication 936 - Home Mortgage Interest Deduction
Official guidance on deducting home mortgage interest
- IRS Schedule A (Form 1040)
Form for itemized deductions including mortgage interest
- IRC Section 163(h) - Interest on Qualified Residence
Tax code section governing mortgage interest deduction rules
This calculator provides estimates. Your actual tax liability may vary. Consult a tax professional for personalized advice. Tax rates and limits accurate as of January 2026.