Mortgage Refinance Calculator
Compare your current mortgage against a refinance option and estimate how long it takes to recover closing costs. This page also keeps the formula, examples, FAQs, and references close by so you can check the result with confidence.
What This Mortgage Refinance Calculator Helps You Do
The break-even period is the closing cost divided by the monthly savings from refinancing. Review the formula and examples below if you want to see how the result is derived.
This page is meant to give you a fast answer, but it also helps you double-check the math before you make a decision. Start with the inputs that you already know, run the calculation, and then compare the output with the formula, examples, and FAQs below so you can see whether the answer fits the situation you are modeling.
If the result looks off, the usual causes are a unit mismatch, a missing decimal, the wrong scenario, or a value that needs to be entered as a rate instead of a total. The notes on this page are designed to make those checks easy without forcing you to leave the calculator and search for context elsewhere.
- Use the calculator first for a quick estimate.
- Use the formula to understand how the result is built.
- Use the examples to compare common use cases.
- Use the references when the answer depends on a standard or assumption.
Common Checks
A quick result is useful, but the best result is one that still makes sense when you look at it a second time. If you are comparing scenarios, try changing one input at a time so you can see which variable has the biggest impact on the final answer. That makes it much easier to spot whether the calculation matches your expectations.
It also helps to keep the context of the problem in mind. A calculator can tell you the math, but you still need to decide whether the input represents a total, a rate, an average, or a category-specific assumption. When in doubt, start with a simple example from the page and scale up from there.
- Check that every unit matches the rest of the problem.
- Keep rates, totals, and averages separate.
- Adjust one variable at a time when testing scenarios.
- Use the smallest realistic input first, then scale upward.
Scenario Planning
This calculator is especially useful when you want a quick answer before you commit time, money, or effort. Try one baseline input set, then change a single number and compare the result so you can see how sensitive the answer is to that variable.
That makes the page useful for more than just arithmetic. It becomes a small decision aid that helps you compare options, test assumptions, and explain the final number with confidence when you need to share it with someone else.
Result
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How to Calculate Mortgage Refinance Calculator
- Enter the current loan details: Use the remaining balance, current rate, and years left on the mortgage.
- Enter the refinance offer: Add the new rate, new term, and closing costs.
- Compare the results: The calculator shows the break-even time and the estimated savings.
Mortgage Refinance Calculator Formula
| Variable | Meaning | Unit |
|---|---|---|
| closing costs | Upfront cost of refinancing | $ |
| monthly savings | Difference between current and refinanced payments | $ |
| break-even | Time needed to recoup the refinancing cost | months |
Worked Examples
- Current balance: $250,000
- Current rate: 6.5%
- Remaining term: 25 years
- New rate: 5.0%
- New term: 25 years
- Closing costs: $3,500
Result: Break-even in a few years
A lower rate can produce meaningful savings if you keep the new loan long enough.
- Current balance: $180,000
- Current rate: 5.8%
- Remaining term: 20 years
- New rate: 4.9%
- New term: 15 years
- Closing costs: $4,000
Result: Faster payoff with smaller monthly savings
A shorter term may save interest even if the monthly payment is only a little lower.
How to Interpret Your Results
| Range | Meaning | Action |
|---|---|---|
| Short break-even | You recover the refinance costs quickly | Check lender fees and any prepayment penalties on the old loan. |
| Medium break-even | The savings exist but take time to recover | Make sure you will stay in the home long enough. |
| Long break-even | The refinance may not be worth the cost | Compare the total interest against staying with the current loan. |
Frequently Asked Questions
References
Last reviewed: April 2026