The bank will quote a monthly payment first. You still need total interest, how extra payments apply, and whether the APR matches what you are comparing.
Loan amortization calculator with extra payments.
Practical tip Start with round numbers from your bank or contract. You can refine decimals after the first pass.
What to enter
Have these handy before you start. Names vary by tool, but the ideas are the same.
Loan amount or remaining balance
Interest rate (APR or nominal, match the contract)
Term in months or years
Extra payment amount and when it starts (if any)
Quick workflow
Fill principal, rate, and term from your contract.
Add extra payment rules if your bank allows them.
Read total interest and payoff date, not only the installment.
Free calculator Use the mortgage payment calculator for P&I, total interest, and amortization on a fixed-rate home loan.
Worked example (illustrative)
Borrow $320,000 at 6.75% for 30 years: monthly P&I is about $2,080 and lifetime interest roughly $428,000. The same balance at 5.75% drops the payment to about $1,870 and saves ~$75,000 in interest over 30 years—but only if you keep the full term. Enter your loan amount, rate, and term in the mortgage calculator; taxes, insurance, and PMI are separate—not a Loan Estimate.
Common search questions
Mortgage payment calculator — principal and interest on a fixed-rate loan.
Home loan calculator — amortization schedule and total interest.
Amortization calculator mortgage — see how early extra principal cuts interest.
Open the tool when you already have a quote, a deadline, or a what-if and need a clear number for loans.
Situations people use it for
Comparing extra payment strategies on a mortgage or car note
Understanding total interest before signing
Refinance break-even with closing costs included
How to read the result
Treat the output as a structured estimate. Small input changes should move the result in a direction that makes sense.
Run a conservative case first. If it still works, you have margin.
Change one field at a time so you know what actually moved the number.
Save the scenario with a name you will recognize later ("2027 refi", "15-year plan").
This model assumes: Loan amortization calculator with extra payments.
Common slip-ups
Comparing APR quotes with different fee structures
Looking only at monthly payment, not total interest
Assuming extra payments apply the way your bank applies them
Try it with your numbers
Open the Loan Amortization calculator, enter your case, and keep a screenshot or PDF if you will revisit the decision. Everything runs in your browser; your inputs are not sent to our servers for the math.