Enter your loan amount, term, and interest rate to see your regular payment and total cost.
This tool assumes a standard amortized loan — the most common structure for personal loans, auto loans, and student loans. Interest compounds monthly on whatever balance is left, and your payment amount stays fixed for the life of the loan.
Each payment is split into two parts: first it covers the interest that accrued on the remaining balance since your last payment, and whatever is left over reduces the principal. Early in the loan, most of your payment goes to interest; by the final payments, almost all of it goes to principal. This is why paying extra toward the principal early on can save a meaningful amount of interest over the full term.
The formula used is the standard amortization equation:
Payment = P × r × (1+r)ⁿ / ((1+r)ⁿ − 1)
Where P is the loan amount, r is the periodic interest rate (the annual rate divided to match your payment frequency), and n is the total number of payments over the loan term.
Say you borrow $20,000 at 6.5% APR over 5 years, paid monthly. That's 60 monthly payments. Plugging those numbers into the calculator above gives a payment of about $391.32 a month, for a total of roughly $23,479 paid over the life of the loan — meaning about $3,479 goes to interest.
If you switched the same loan to a 3-year term instead of 5, your monthly payment would rise, but your total interest paid would drop significantly, since you're borrowing the money for less time.
What's the difference between the interest rate and APR?
APR (Annual Percentage Rate) is the yearly cost of borrowing including most fees, expressed as a percentage. This calculator treats the rate you enter as the APR, compounded monthly, which matches how most consumer loans are quoted.
Does paying weekly instead of monthly save money?
Switching payment frequency alone (with the same APR and term) makes only a small difference. The bigger savings come from a shorter term or a lower rate — or from making extra principal payments.
Why is my total interest so much lower or higher than I expected?
Total interest is extremely sensitive to loan term. Doubling your loan term roughly doubles the number of payments, so even a small monthly payment reduction can mean paying substantially more interest overall.
Is this calculator accurate for mortgages?
The math is the same, but for home loans use our dedicated Mortgage Calculator, which separates out the down payment and home price.
Using the amortization formula based on principal, interest rate, and term, producing a fixed periodic payment.
Interest is calculated on the outstanding balance, which is highest early in the loan.
A longer term lowers monthly payment but increases total interest paid over the loan's life.