Business
Estimate monthly payments, total interest, and payoff timing for a fixed-rate loan.
Enter your numbers to see the answer.
Loan calculator guide
Loan cost depends on the principal borrowed, the interest rate, the term, any fees, and how quickly you repay. This calculator uses the standard amortization formula for a fixed-rate loan with monthly payments to find the regular payment, then builds the full schedule so the total interest, total cost including any origination fee, and payoff time are visible rather than hidden behind one monthly number. An optional extra monthly payment shows how much interest early repayment saves and how many months it removes from the term. It suits car loans, personal loans, student loans with a fixed rate, and small business borrowing. The result excludes taxes, insurance, late fees, variable-rate resets, and lender-specific rules, and the market, effective date, source, and review fields exist so a rate assumption can be traced rather than treated as current. It is not a loan offer or financial advice.
Monthly payment = P × r(1 + r)^n ÷ ((1 + r)^n − 1), where P is principal, r = annual rate ÷ 12 ÷ 100, and n = years × 12. Total interest = sum of monthly interest across the schedule. Total loan cost = total paid + origination fee. A zero-rate loan is principal ÷ n.
Worked example with the defaults: a $25,000 loan at 6.5% over 5 years has a monthly rate of 0.065 ÷ 12 = 0.005417 and 60 payments. The payment is $25,000 × 0.005417 × 1.005417⁶⁰ ÷ (1.005417⁶⁰ − 1) = $489.15, which is the monthly principal-and-interest figure the calculator displays. Sixty payments total 60 × $489.15 = $29,349.22, so total interest is $29,349.22 − $25,000 = $4,349.22, and with no origination fee the total loan cost is $29,349.22 over a payoff time of 5 years. Adding a $100 extra payment each month clears the loan in about 49 months and saves about $865 of interest.
Enter the loan amount in currency, the annual rate as a percentage such as 6.5 (not 0.065), and the term in years; the calculator converts to a monthly rate and monthly payment count. Extra payment is currency per month applied to principal, and the origination fee is a one-off amount added to total cost, not financed. Confirm whether fees are included in the financed amount; if they are, add them to the loan amount instead.
Use payment, total repayment, and interest together when comparing offers. A lower monthly payment may come from a longer term and higher total cost, and the extra-payment row shows the trade-off in the other direction.
Do not compare offers with different fees, terms, or rate types using the payment alone: stretching the default loan to 7 years drops the payment to $371 but raises total interest from $4,349 to about $6,180. Do not enter APR as the interest rate if the lender quotes both, because APR already folds in fees and will double count them with the origination field. Do not assume a variable or promotional rate stays fixed for the term, and do not ignore prepayment penalties when relying on the extra-payment savings figure. Taxes, insurance, and late fees are excluded from every row.
Verify the lender’s disclosure, APR, fees, and repayment rules before signing.
Sources
How it works
Estimate monthly payments, total interest, and payoff timing for a fixed-rate loan. This tool explains the calculation so you can adjust the assumptions to match your situation.
Worked example
With Loan amount = 25000 $ · Annual interest rate = 6.5 % · Loan term = 5 years · Extra monthly payment = 0 $ · Origination fee = 0 $ → $489.15 (monthly principal-and-interest payment). Change an input above and this example updates with your numbers.
Loan payment basics
A fixed-rate loan payment usually combines principal and interest. The principal reduces what you owe; interest is the cost of borrowing. A longer term can lower the monthly payment but usually increases total interest. Use the optional extra payment field to see how paying more each month may shorten the payoff time.
The calculator uses the standard amortizing-loan formula with the loan amount, monthly interest rate, and number of monthly payments. It also provides a month-by-month amortization schedule so you can see how each payment is divided.
Common questions
The interest rate describes the cost of borrowing the principal. APR adds certain lender fees and expresses the total as an annual percentage, so it is the better comparison measure when the lender provides it; enter the plain rate here and the fee separately.
It shows the cost of borrowing across the full term, not just the amount due in one month. The default $25,000 loan costs $4,349.22 in interest over five years, about 17% of the amount borrowed, and that figure grows quickly with a longer term.
Extra payments go straight to principal, so every later month accrues less interest. Adding $100 a month to the default loan repays it roughly 11 months early and saves about $865; the calculator shows the saving on the extra payment impact row.
At 6.5% over 5 years the payment is $489.15. At 4 years it rises to about $593, and at 6 years it falls to about $420 while total interest climbs to around $5,260, so the term you choose matters as much as the rate.
No. It covers principal, interest, an optional origination fee, and extra payments only. Sales tax on a vehicle, gap or credit insurance, late fees, and documentation charges must be added separately or rolled into the loan amount if you finance them.