Refinance vs Keep vs Recast Calculator
Compare three paths from the same current debt, including fees and the amount still owed at one future date.
Your inputs
Use consistent units and periods. Defaults are examples.
Your result
Check the assumptions below before relying on a result.
Formula and method
Keep the present loan, replace it with a loan of principal plus financed costs, or reduce principal and recast at the original rate and remaining term. For every option calculate upfront cash + scheduled payments through month h + remaining principal at month h. Financed fees enter the new balance once and are not also counted as upfront cash.
Worked example
Refinancing at exactly the same rate and remaining term with no fees reproduces the original schedule and has zero economic advantage. A longer new term can reduce the payment while leaving a larger future balance; the equal-date comparison shows that liability.
Related calculations
Mortgage Recast Calculator
Compare a lower recast payment with keeping the old payment after the same principal reduction.
Open calculator ↗Points and ratesMortgage Points & Economic Break-Even Calculator
Compare two rate offers with points, lender credits, fees and the debt remaining at your chosen date.
Open calculator ↗PrepaymentMortgage Extra Payment Planner
Model recurring, annual and one-off principal reductions with a full allocation ledger.
Open calculator ↗How to use this result
- Enter the existing balance, rate and remaining months.
- Separate cash closing costs from costs financed in the new loan.
- Enter an optional principal reduction for the recast option.
- Compare horizon cash plus payoff, then inspect each full schedule and the monthly-payment tradeoff.
Questions about this calculation
Does a lower refinance payment prove I save money?
No. A longer term or financed fees can leave more principal later. Compare the same date and include the remaining payoff.
Why count the recast lump sum as cash?
It is money you pay now to reduce the debt. Ignoring it would give the recast option an artificial advantage.
Can I model cash-out refinancing?
Not here. Comparing unequal cash received needs an explicit reconciliation; this tool keeps the same original debt without cash out.