Practical guide
Understanding mortgage refinance check — sensitivity table
Everyday editorial team · GEOINNOVATION CO., LTD · Published · Updated
What this calculation is for
Refinancing replaces a debt with new terms. A useful comparison includes closing costs, the remaining old term and the proposed new term, not just the interest rate. A smaller monthly payment can come from extending the debt rather than reducing total cost.
How the method works
The tool calculates current and proposed fixed-rate principal-and-interest payments. In this model, entered refinance costs are financed in the new balance. It also shows a simple fee-to-payment-savings break-even measure, which is a cash-flow heuristic rather than a full investment valuation.
A worked example
A $3,000 cost and a $100 monthly reduction imply a simple 30-month break-even. If you expect to sell or repay in 12 months, that reduction alone would not recover the cost over your expected holding period.
Assumptions and real-world differences
Compare total interest and remaining balances as well as payments. The simplified break-even omits tax effects, discounting, payoff penalties and changes to insurance or escrow. Financing the costs adds interest beyond their face amount.
Reading the remaining loan balance sensitivity table
The tool evaluates the same model across a range of remaining loan balance values while holding other assumptions constant. Choose a realistic low value, high value and number of points. Each row reports the same headline measure; the table is a set of conditional calculations, not a probability distribution or a forecast. Input-step rounding can make nearby rows equal.
Reproduce this tool’s example
These fixed example inputs are independent of edits you make above. Enter them in this tool to reproduce the result, then replace them with your own assumptions.
- Minimum remaining loan balance
- 120,000 $
- Maximum remaining loan balance
- 360,000 $
- Number of comparison points
- 5 points
- Current APR
- 7 %
- New APR
- 6.25 %
- Current remaining term
- 24 years
- New loan term
- 20 years
- Refinance closing costs
- 4,500 $
Sensitivity analysis: 5 comparison points
Remaining loan balance ranges from $120,000 to $360,000.
- Remaining loan balance: $120,000: $-48.69
- Remaining loan balance: $180,000: $-56.6
- Remaining loan balance: $240,000: $-64.5
Frequently asked questions
- Is a lower rate always worthwhile?
- No. Fees, term changes and your time horizon can outweigh the rate reduction.
- Does break-even prove I should refinance?
- No. It is one simplified measure, not a recommendation or a net-present-value analysis.
- Does the most favorable row show the most likely outcome?
- No. The table assigns no likelihood to any row. It shows how the result responds to the chosen assumption, and you remain responsible for selecting a plausible range.