How they differ
Under the hood, Auto Refinance Calculator uses payment delta versus upfront cost recovery fed by current balance, current rate, new rate, fees, hold period. Mortgage Refinance Break-Even uses monthly payment delta vs upfront cost recovery fed by current rate, new rate, closing costs, remaining balance. The two are not substitutes; they answer adjacent questions in your workflow.
Pick Auto Refinance Calculator when your question is about auto refinance and your inputs are current balance, current rate, new rate, fees, hold period. Pick Mortgage Refinance Break-Even when the question shifts to mortgage refinance break-even and your inputs become current rate, new rate, closing costs, remaining balance. If neither matches what you need, the Real Estate category hub lists every tool we have for related questions.