Mortgage Refinance Calculator: Is It Worth It for Your Family?

Enter your current loan and the new rate you've been quoted to see your monthly savings, how many months until the closing costs pay for themselves, and total interest saved over time. Not financial advice — a fee-only advisor can model the full picture including your tax situation.

When refinancing makes sense for families

Most financial planners use a simple rule: refinancing is worth it if you break even on closing costs before you plan to move. But for families, a few additional factors complicate the picture.

The term reset trap

Refinancing a 26-year loan into a new 30-year loan at a lower rate can increase total interest paid even as it reduces monthly payments. That's because you're paying interest on the balance for 4 extra years. The calculator above shows your total interest comparison — check it before committing. A 20-year loan often hits a better balance: lower monthly payment than keeping your current loan, lower total interest than a 30-year.

Rate-and-term vs. cash-out refinancing

Rate-and-term refinance: You borrow the same amount at a new rate — or close to it. This is what the calculator above models. The math is clean: you're trading closing costs for a lower rate.

Cash-out refinance: You borrow more than you owe and receive the difference as cash. This is often used for home improvements, college funding, or high-rate debt consolidation. The math is more complex: you're taking on a larger loan balance, so the monthly payment comparison is less meaningful. A fee-only advisor can model whether this makes sense relative to alternatives like a HELOC.

The mortgage interest deduction in 2026

Mortgage interest is only deductible if you itemize — meaning your total deductions (mortgage interest + SALT + other) exceed the standard deduction of $32,200 MFJ in 2026.¹ With the SALT cap raised to $40,400 (OBBBA 2025), some families near major metros now cross the itemization threshold again.² But for most families earning $150K–$400K, the standard deduction is still larger, making mortgage interest effectively non-deductible at the margin — which means your true cost of borrowing is the stated rate, not a lower after-tax rate.

If you do itemize, refinancing to a lower rate reduces your deductible interest, which partially offsets the savings. The calculator above accounts for this when you select "Yes — I itemize."

PMI and the 80% LTV milestone

If you're currently paying private mortgage insurance (PMI) because your equity is below 20%, a refinance that brings your loan-to-value below 80% could eliminate PMI — adding to your true monthly savings beyond what the rate difference shows. PMI typically runs 0.5%–1.5% of the loan amount annually ($158–$475/month on a $380K loan), so eliminating it can be significant. OBBBA (2025) restored the PMI deductibility provision, but only matters if you itemize.³

Timing a refinance around a major life event

For dual-income families, a few situations make refinancing especially worth evaluating:

• Before one spouse leaves the workforce (parental leave, early retirement, caregiving year): lenders qualify based on current income. Once income drops, your rate lock and approval are based on the old picture.
• Before a big tuition year: if you're considering a cash-out refi to pay for college costs, do it before you start tapping 529s — assets and income matter differently in different contexts.
• After reaching 20% equity: if you're approaching the PMI cancellation threshold, doing the math on a refi that bumps you to 80% LTV can pay off doubly — new rate plus PMI elimination.

The opportunity cost angle

Closing costs are typically $3,000–$6,000. If that money instead went into a tax-advantaged account or paid down higher-rate debt, would you come out ahead? The mortgage payoff vs. investing calculator can help model that tradeoff.

FamilyAdvisorMatch is a referral service, not a licensed advisory firm. We may receive compensation from professionals in our network. Content is for informational purposes only and does not constitute financial, tax, legal, or investment advice.