Loan Calculator
A general-purpose calculator for any fixed-rate installment loan: find your payment and total interest.
Understanding the Loan Calculator
The same math behind every fixed-rate loan
This is the general-purpose version of the same amortization math used for mortgages, auto loans, and personal loans: a fixed monthly payment that covers both interest and principal, structured so the balance reaches exactly zero at the end of the term.
Why the payment split shifts over time
Early payments are weighted more toward interest, since interest is calculated on the outstanding balance, which is largest at the start. As a result, as the balance shrinks, more of each fixed payment goes toward principal — the payment amount stays flat, but its composition shifts over time.
When to use this over a more specific calculator
Use this tool for any loan that doesn’t fit a more specific calculator on this site — for example, student loans, equipment financing, or a private note between individuals — as long as it uses a fixed rate and a fixed term.
See it in practice
Example 1 — Four-year installment loan
Example 2 — Smaller loan, shorter term
Common questions
It works for any fixed-rate, fixed-term installment loan repaid in equal monthly payments. However, for loans with points, origination fees, or other upfront costs, the APR calculator will give you the more complete real cost.
Run the calculator at your current rate for a baseline. Then, rerun it at a higher plausible rate to see how much your payment could rise if the rate adjusts upward.
For that, use the debt payoff calculator, which supports adding an extra monthly payment on top of the required minimum and shows the resulting payoff time and interest savings.
A longer term spreads the same principal over more months, which lowers the monthly payment but gives interest more time to accrue on the outstanding balance. In other words, the trade-off is a lower payment for a higher total cost.
Monthly payments on a fixed-rate installment loan are calculated using the loan amount, interest rate, and term. As a result, the balance reaches exactly zero on the final payment, with interest accruing on the remaining balance each period.
A secured loan is backed by collateral, like a house or car, which the lender can seize if you default. An unsecured loan, on the other hand, has no collateral, which typically means a higher interest rate to offset the lender’s added risk.
Most loans allow early payoff without penalty, reducing your total interest paid. That said, some older or specific loan products carry prepayment penalties, so it’s worth confirming your specific loan terms before making large extra payments.
Yes, credit score is one of the most significant factors lenders use to set your interest rate. Generally, a higher score unlocks a lower rate, which can meaningfully reduce your total interest cost over the life of the loan.