Mortgage Refinance Calculator 2026

When Should You Refinance Your Mortgage?

Refinancing replaces your existing mortgage with a new one — ideally at a lower interest rate. The decision hinges on one key number: your break-even point — how many months until your monthly savings exceed the closing costs you paid to refinance.

The 2% rule of thumb: Refinancing typically makes sense when you can reduce your interest rate by at least 0.75%-1%. However, the break-even calculation is more precise. If you plan to stay in the home for longer than the break-even period, refinancing saves money.

Real-Life Example: $300,000 Loan

Current rate: 7%, remaining: 25 years. New rate: 6.5%. Current monthly payment: $2,122. New payment: $2,027. Monthly savings: $95. Closing costs: $5,000. Break-even: 53 months (4.4 years). If you plan to stay 5+ years, refinancing saves $28,500 total over the remaining 25 years.

Types of Refinancing

• Rate-and-term refi: Lower your rate or change the term (most common)
• Cash-out refi: Access home equity — borrow more than you owe, difference paid in cash
• Streamline refi: FHA and VA loans have simplified refinancing with less documentation

Understanding the Full Picture

Financial calculators give you numbers — but numbers without context lead to poor decisions. This section explains the broader framework around this calculation so you can use the result intelligently in your financial planning.

How This Fits Into Your Overall Financial Plan

No financial calculation exists in isolation. Every number here connects to others. Your mortgage payment affects your DTI and how much you can save. Your 401(k) contribution affects your taxable income and current cash flow. Your effective tax rate determines whether Roth or traditional accounts benefit you more. The most financially successful Americans do not optimize individual numbers — they optimize the entire system together.

The Priority Order Most Financial Planners Recommend

Step 1: Build a $1,000 emergency fund. Step 2: Capture your full employer 401(k) match — this is an instant 50-100% return on that money. Step 3: Pay off high-interest debt (above 7%). Step 4: Max your HSA if eligible — the only triple-tax-advantaged account in the US tax code. Step 5: Max your IRA (Roth or Traditional depending on income). Step 6: Return to 401(k) up to the annual limit. Step 7: Build a 3-6 month emergency fund. Step 8: Invest in taxable brokerage. Following this order maximizes the tax efficiency of every dollar saved.

Common Calculation Mistakes to Avoid

Using gross income instead of net income for budgeting — your take-home is 25-35% less than gross for most Americans. Forgetting to account for inflation — $1,000/month in retirement expenses today will cost $1,806/month in 20 years at 3% inflation. Assuming a single rate of return — markets do not return 10% every year. Modeling only the average case rather than stress-testing against worst-case historical scenarios like 2000-2009 (the "lost decade") or 2008 alone (-37%). Ignoring sequence-of-returns risk — retiring into a bear market is far more damaging than a bear market mid-career.

When to Consult a Professional

Use this calculator as a starting point for your own research and planning. For decisions involving more than $50,000, complex tax situations (business income, stock options, inheritance), multi-state residency, divorce, or retirement transition, working with a fee-only Certified Financial Planner (CFP) is worth the cost. Fee-only planners charge by the hour or flat fee — they earn nothing from selling you products. Find one at NAPFA.org or CFP.net.

Data Privacy Note

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