PFCGuide · PFC
How to Use the Refinance Calculator
Follow a step-by-step refinance calculator guide. Enter loan terms and closing costs, choose a horizon, and interpret savings, break-even, and balances.
Free calculators. No sign-up required.
Last updated:
The PFC refinance calculator compares keeping a fixed-rate mortgage with replacing it. It reconstructs the existing principal-and-interest payment from your balance, interest rate, and remaining term, then compares the two loans through a month you choose.
1. Gather your current loan and proposed offer
Use your latest balance and remaining scheduled term for the existing loan. For the replacement, use a Loan Estimate with the proposed interest rate, term, and costs. Enter the contract rate, not APR. APR includes certain costs and is not the rate used to calculate this model’s monthly payment.
Source: CFPB: understanding your Loan Estimate.
2. Enter the loan terms and costs
| Field | What to enter |
|---|---|
| Current mortgage balance | Remaining principal, not the original purchase loan |
| Current mortgage rate | Existing fixed contract interest rate |
| Months left on current loan | Remaining months, not the original term |
| New mortgage rate | Proposed fixed contract rate |
| New loan term | Years in the replacement loan |
| Refinance closing costs | Total transaction costs you want the comparison to include |
| Pay closing costs | In cash at closing, or finance into the new loan |
| Comparison horizon | Months until you expect to sell, refinance again, or review |
Include points in the total costs; there is no separate points field. Review lender credits and distinguish transaction costs from escrow deposits or prepaid expenses that are not all incremental refinance costs. The calculator has one cost total and one payment choice, so split cash/financed arrangements require a separate calculation. Do not count financed costs twice by adding them to the current balance.
3. Choose a meaningful comparison month
A five-year comparison uses 60 months. If your plans are uncertain, repeat with a shorter and a longer horizon. Click Calculate, then read the net savings result and the current and new payment amounts. A negative payment reduction means the new payment is higher.
4. Reproduce the example
Enter a $250,000 balance at 7%, 300 months left, a 6% replacement rate, a 30-year new term, $5,000 costs paid in cash, and a 60-month horizon. These are hypothetical inputs.
| Output | Estimate |
|---|---|
| Current monthly payment | $1,766.95 |
| New monthly payment | $1,498.88 |
| Initial payment reduction | $268.07 |
| Net savings at month 60 | $6,353.76 |
| First nonnegative month within horizon | 25 |
5. Inspect the breakdown before comparing offers
Open View breakdown to inspect monthly payments, both remaining balances, and net savings. Download CSV to keep the full comparison, and label your saved file with the quote and assumptions. The headline savings include outstanding debt, so they are not simply the payment reduction multiplied by 60 minus closing costs.
The tool assumes fixed, fully amortizing loans and scheduled payments. It excludes cash-out, mortgage insurance, property taxes, other unentered fees, and opportunity cost. It does not model ARM resets or future extra payments. Reconcile an unusual current payment or servicing schedule before relying on the estimate.
Next, use the refinance scenario comparison to explore shorter terms or financing costs. Read the costs and break-even article for more context.