Compare the remaining payment and borrowing cost of a current fixed-rate mortgage with a proposed replacement.
It keeps the property value, balance, cash amounts, rate convention, payment timing, and comparison horizon visible so the result can be checked against an actual quote, statement, budget, or contract.
Calculation structure
Follow the money through time
Both options use level-payment amortization; proposed borrowing cost includes separately entered refinancing costs.
Visual explanation
See which inputs change the result
Action todayCash or fee
→
Future effectPayment + interest
Both options use level-payment amortization; proposed borrowing cost includes separately entered refinancing costs.
Read the estimate correctly
Use the result with its assumptions
Compare 250,000 over 240 remaining months at 6% with a new 240-month mortgage at 5% and 4,000 of costs.
Comparing different terms can lower the payment while increasing lifetime cost. Taxes, penalties, and cash-flow opportunity cost are excluded.
Quick guide
How to use this calculator
Enter the figures from the offers, statement, or transaction estimate you want to examine.
Keep every amount in one consistent currency and use the rate and period convention shown by each label.
Compare the result with the visible assumptions before making a decision.
Calculation method
Calculation method
Both options use level-payment amortization; proposed borrowing cost includes separately entered refinancing costs.
Calculations retain full precision internally and round only for presentation. Invalid, non-repaying, out-of-range, and numerically unreliable inputs are rejected.
Worked example
Practical example
Compare 250,000 over 240 remaining months at 6% with a new 240-month mortgage at 5% and 4,000 of costs.
Both options use level-payment amortization; proposed borrowing cost includes separately entered refinancing costs.
Supported inputs
Precision and limits
Visible limits
Amounts are capped at 1e12, rates at 1000%, and mortgage terms at 1,200 whole months.
International scope
No currency, country, tax system, fee schedule, lender policy, regulated APR definition, or market rate is assumed.
Decision boundary
These results are mathematical comparisons of entered scenarios, not an offer, approval, legal disclosure, valuation, or recommendation.
Calculator-specific assumptions
Comparing different terms can lower the payment while increasing lifetime cost. Taxes, penalties, and cash-flow opportunity cost are excluded.
