Refinance Calculator

Compare your current mortgage against a refinance option and estimate the new payment, savings, and break-even time. This page also keeps the formula, examples, FAQs, and references close by so you can check the result with confidence.

What This Refinance Calculator Helps You Do

Refinancing can lower your payment if the new rate saves more each month than the upfront cost adds back. 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.

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Result

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Quick Answer: Refinancing can lower your payment if the new rate saves more each month than the upfront cost adds back. Review the formula and examples below if you want to see how the result is derived.

How to Calculate Refinance Calculator

  1. Enter current mortgage details: Set the remaining balance, current rate, and years left.
  2. Enter refinance terms: Add the new rate, new term, points, closing costs, and any cash out.
  3. Review the refinance outcome: The calculator shows payment, savings, break-even, and total interest impact.

Refinance Calculator Formula

Break-even months = upfront costs ÷ monthly savings
Variable Meaning Unit
Upfront costs Closing costs plus mortgage points $
Monthly savings Difference between the current and refinanced payments $
New loan amount Amount rolled into the refinance $

Worked Examples

USA - Lower rate refinance
  • Current balance: $250,000
  • Current rate: 6.5%
  • Remaining term: 25 years
  • New rate: 5%
  • New term: 25 years
  • Closing costs: $3,500
  • Mortgage points: 0%
  • Cash out amount: $0

Result: New monthly payment = $1,461.45

A lower rate can reduce the monthly payment substantially.

UK - Break-even check
  • Current balance: $250,000
  • Current rate: 6.5%
  • Remaining term: 25 years
  • New rate: 5%
  • New term: 25 years
  • Closing costs: $3,500
  • Mortgage points: 1%
  • Cash out amount: $0

Result: Break-even time = 92.35 months

Points increase the upfront cost and extend the payback period.

EU - Cash-out refinance
  • Current balance: $250,000
  • Current rate: 6.5%
  • Remaining term: 25 years
  • New rate: 5%
  • New term: 25 years
  • Closing costs: $3,500
  • Mortgage points: 1%
  • Cash out amount: $20,000

Result: New loan amount = $275,000

Cash out adds to the refinanced balance and raises the amount financed.

Frequently Asked Questions

Start with the new payment and break-even time, then look at total interest saved.

Yes. Points are usually financed or paid upfront, so they affect the refinance cost.

No. Cash out raises the new loan amount but gives you cash at closing.
Planning note: This is a simplified mortgage estimate and does not include taxes, escrow changes, or lender-specific fees.

References

Last reviewed: April 2026