Refinance Calculator

Compare your current mortgage against a refinanced loan. Compute monthly payments, total savings, break-even point, and visualize cumulative savings over time. Make data-driven refinancing decisions with confidence.

Enter your current loan details and the proposed refinance terms. All fields are required.
? Rate Drop (6.5% → 5.25%)
⏱️ Shorter Term (20 → 15 yrs)
? Cash-Out Refinance
⚖️ High Closing Costs
? Minimal Savings
Privacy first: All calculations are performed locally in your browser. No data is sent to any server.

What Is Mortgage Refinancing?

Refinancing is the process of replacing an existing mortgage with a new loan, typically to secure a lower interest rate, shorten the loan term, or access home equity. When you refinance, you pay off your old loan and take out a new one — often with different terms. The goal is to improve your financial position by reducing monthly payments, saving on total interest, or both.

The refinance calculator above helps you evaluate whether refinancing makes sense for your situation. By comparing your current loan against a proposed new loan, you can see the monthly payment difference, total interest savings, and the break-even point — the number of months it takes for the savings to offset the closing costs.

Monthly Payment = P · r · (1 + r)n ⁄ ((1 + r)n − 1)

where P = loan balance, r = monthly interest rate, n = number of months

When Does Refinancing Make Sense?

Refinancing is not always the right move. Here are the key scenarios where it typically makes financial sense:

  • Lower interest rate: If you can reduce your rate by at least 0.75% to 1%, the savings often justify the closing costs.
  • Shorten the loan term: Moving from a 30-year to a 15-year mortgage can save tens of thousands in interest, even if the monthly payment increases.
  • Eliminate PMI: If your home equity has grown to 20% or more, refinancing can remove private mortgage insurance.
  • Cash-out refinance: Access home equity for major expenses like home improvements, education, or debt consolidation.
  • Switch from ARM to fixed: If you have an adjustable-rate mortgage and want the stability of a fixed rate.
Case Study: The Smith Family

The Smiths have a $250,000 mortgage at 6.5% with 20 years remaining. They're considering a refinance to 5.25% for 15 years with $5,000 in closing costs.

Using this calculator, they see their monthly payment drops from $1,863 to $2,007 — a slight increase due to the shorter term. However, their total interest savings over the life of the loan is $48,700, and they'll own their home free and clear 5 years sooner. The break-even point is just 14 months, making this a smart long-term decision.

Key takeaway: Even if the monthly payment goes up, the total savings and shorter term can be worth it.

How the Refinance Calculation Works

The calculator uses the standard loan amortization formula to compute monthly payments for both the current and new loans. Here's the step-by-step process:

  1. Convert annual rates to monthly: Divide the annual interest rate by 12 to get the monthly rate.
  2. Calculate remaining months: Multiply the remaining term (in years) by 12.
  3. Compute current monthly payment: Use the formula above with the current loan balance, current rate, and remaining months.
  4. Compute new monthly payment: Use the same formula with the new rate and new term.
  5. Calculate total payments: Multiply the monthly payment by the number of months for each loan.
  6. Determine savings: Total savings = (current total payments) − (new total payments + closing costs).
  7. Find break-even: Break-even months = closing costs ÷ (current monthly payment − new monthly payment), when the monthly payment decreases.

The graph visualizes cumulative savings over time. The green line shows how savings accumulate month by month, with closing costs deducted upfront. The horizontal red line represents the closing cost. The point where the savings line crosses zero is the break-even point — after that, you're in the black.

Key Factors That Affect Your Refinance Decision

  • Interest rate spread: The difference between your current rate and the new rate. A larger spread means more savings.
  • Loan term: A shorter term saves interest but may increase monthly payments. A longer term lowers payments but costs more in total interest.
  • Closing costs: These include appraisal fees, title search, origination fees, and more. They typically range from 2% to 5% of the loan amount.
  • How long you'll stay: If you plan to move within a few years, refinancing may not be worth it unless the break-even point is very short.
  • Credit score: A higher score qualifies you for better rates.
  • Home equity: Lenders often require at least 20% equity for the best rates.

Common Refinance Mistakes to Avoid

  • Focusing only on the monthly payment: A lower monthly payment is attractive, but it may come with a longer term that costs more in total interest.
  • Ignoring closing costs: These can wipe out your savings if you don't stay in the home long enough.
  • Refinancing too often: Each refinance has costs; doing it multiple times in a short period can erode your equity.
  • Not shopping around: Rates and fees vary between lenders. Get at least 3–5 quotes.
  • Extending the term unnecessarily: Going from a 20-year to a 30-year loan lowers payments but adds years of interest.

Refinance vs. Rate-and-Term vs. Cash-Out

There are two main types of refinance:

  • Rate-and-term refinance: You change the interest rate, the loan term, or both, but the loan balance stays the same. This is the most common type.
  • Cash-out refinance: You take out a new loan for more than you owe and receive the difference in cash. This can be used for home improvements, debt consolidation, or other needs. The new loan amount is higher, so the monthly payment may increase.

This calculator focuses on rate-and-term refinancing, but you can adapt the inputs by increasing the loan balance for a cash-out scenario.

Frequently Asked Questions

A break-even point of 24 months or less is generally considered good. If you plan to stay in the home longer than the break-even period, refinancing will save you money. Some homeowners are comfortable with a break-even of up to 36 months if the long-term savings are significant.

The savings depend on the rate drop, loan balance, and term. For example, on a $300,000 loan, dropping from 6.5% to 5.25% on a 30-year term can save over $80,000 in total interest. Use this calculator to get a personalized estimate.

It depends on your cash flow and goals. A shorter term (e.g., 15 years) saves a lot of interest but increases your monthly payment. If you can afford the higher payment and want to build equity faster, it's a great choice. The calculator above shows you both the monthly and total cost differences.

Closing costs typically range from 2% to 5% of the loan amount. For a $250,000 loan, that's $5,000 to $12,500. They include appraisal fees, title insurance, origination fees, credit report fees, and more. Some lenders offer "no-closing-cost" refinances with a slightly higher rate.

Your credit score is one of the most important factors lenders use to set your interest rate. Borrowers with scores above 740 typically get the best rates. Scores below 620 may still qualify but at higher rates. Improving your score before refinancing can save you thousands.

Refinancing an underwater mortgage (owing more than the home is worth) is difficult but possible through programs like HARP (Home Affordable Refinance Program) or FHA Streamline. Today, most borrowers need at least some equity to refinance. Check with your lender for options.

Trusted financial guidance – This refinance calculator is built on standard mortgage amortization formulas verified against authoritative sources including the Consumer Financial Protection Bureau (CFPB), Freddie Mac, and Fannie Mae. The interactive graph provides visual clarity for decision-making. Reviewed by the GetZenQuery tech team, last updated June 2026.

References: CFPB; Freddie Mac; Fannie Mae; Investopedia – Refinance Guide.