Refinance Calculator

What is a refinance calculator?

A refinance calculator compares your current loan — balance, rate, and time remaining — against a new loan at a lower rate, including closing costs, to show your new monthly payment, break-even point, and whether you actually save money.

How this calculator works

• Enter your current balance, interest rate, and how many months are left on the loan.
• Enter the new rate, the new term you’re considering, and the closing costs you’d pay to refi.
• It computes both monthly payments and the total interest paid over each loan’s remaining life.
• Break-even is the number of months before the monthly savings cover the closing costs.

How to use the result

1. Check the monthly payment change first — a lower payment is only useful if it frees cash you actually need.
2. Look at total interest change. Refinancing into a longer term can lower the payment while increasing lifetime interest — the calculator catches that.
3. Compare break-even against how long you plan to keep the loan. If you’ll sell before break-even, refi usually isn’t worth it.
4. Run the numbers with your real closing-cost quote — $3,000 vs. $6,000 in fees changes the answer dramatically.

When does refinancing make sense?

Refinancing pays off when the new rate is meaningfully lower, you plan to stay in the loan past the break-even point, and you can absorb the closing costs. A common rule of thumb is that a rate drop of at least one percentage point makes refi worth exploring — but the exact answer depends on your balance and term, which is what this calculator is for.

Common mistakes

• Comparing only the monthly payment. A longer term lowers the payment but can add thousands in interest.
• Ignoring closing costs. If break-even is 40 months and you’ll move in 24, the refi loses money.
• Resetting the clock. Going from 20 years left to a new 30-year term can restart your interest payments almost from scratch.

Refinancing is really a math question about interest rates — the same compounding engine behind the retirement calculator. For a car, run the same comparison on the auto loan calculator before switching lenders.