Mortgage Tax Deduction Calculator

The mortgage interest deduction is one of the biggest tax benefits of homeownership — but the 2017 Tax Cuts and Jobs Act changed the rules significantly. This calculator shows your actual after-tax mortgage cost and whether itemizing makes sense for you.

Your mortgage & tax situation

Loan amount

Interest rate

Filing status

Federal tax bracket

Annual property taxes

Other itemized deductions

Charitable giving, state/local taxes, etc.

Year 1 interest paid

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Tax deductible amount

Annual tax savings

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If itemizing benefits you

After-tax mortgage rate

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Effective cost of borrowing

Monthly tax benefit

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Avg monthly savings

Standard deduction (your filing status)—

Your itemized deductions total—

Benefit of itemizing—

Should you itemize?—

Year 1 tax savings (if itemizing)—

5-year cumulative tax savings—

Your effective after-tax rate—

What changed with the 2017 tax reform?

The Tax Cuts and Jobs Act of 2017 made two major changes: (1) The standard deduction nearly doubled — to $30,000 for married filers in 2026. This means far fewer homeowners benefit from itemizing. (2) The mortgage interest deduction was capped at loans up to $750,000 (reduced from $1 million). Additionally, the SALT (state and local tax) deduction was capped at $10,000/year. For many middle-class homeowners, the standard deduction is now larger than their itemized deductions, so they receive no mortgage interest benefit.