Loan Payment Calculator

A fixed-rate installment loan spreads repayment across equal monthly payments using standard amortization. Each payment covers interest on the remaining balance first, then applies the rest to principal. Early in the term, most of the payment is interest; near the end, most goes to principal. The payment amount stays constant while the interest/principal split shifts every month.

The payment formula is PMT = P × [r(1+r)^n] ÷ [(1+r)^n − 1], where P is loan principal, r is the monthly rate (annual APR ÷ 12 ÷ 100), and n is the number of monthly payments (years × 12). At 0% APR, payment simplifies to P ÷ n.

Defaults illustrate a $25,000 auto or personal loan at 6.5% APR for 5 years (60 payments). Monthly rate r = 0.065 ÷ 12 ≈ 0.005417. Plugging into the formula yields about $489.15 per month. Over 60 payments you pay roughly $29,349 total, meaning about $4,349 in interest on top of the $25,000 borrowed — verify on your lender’s disclosure for exact cents.

APR versus note rate: this tool treats the annual field as the nominal rate divided by 12. It does not separate finance charges, prepaid interest, or APR-includes-fees calculations required on some Truth-in-Lending disclosures. Enter the rate your loan estimate shows for monthly payment planning.

Extra principal payments are not modeled. Paying $50 more toward principal each month shortens the term and cuts total interest, but the scheduled payment here assumes no prepayment. Biweekly half-payments (26 per year) also retire loans faster than 12 full monthly payments — a different schedule.

Common mistakes include entering the monthly payment as the rate, using the loan term in months in the years field without converting, and comparing a 72-month car loan payment to a 48-month payment without looking at total interest. Always compare total cost, not just the monthly number.

Refinancing replaces one loan with another at a new rate and term — rerun with the new principal (often old balance plus fees), new APR, and new years to compare payment drops versus total interest.

Auto loans sometimes quote money factor on leases — this page is installment loan amortization only, not lease money-factor math.

Total interest line helps compare 60-month versus 48-month terms at the same rate — longer terms drop payment but raise total interest even when APR is identical.

Co-signers do not change the amortization math — payment is the same; credit risk falls on both parties if the primary borrower defaults.

Mortgage calculators add escrow for taxes and insurance — this daily loan tool is generic; housing shoppers should budget escrows separately from principal and interest.

Simple interest loans (some private notes) charge interest on original principal only — this page uses amortizing compound monthly interest typical of bank installment loans.

Compare total paid line to principal to see how much interest the term costs — shortening years in the form drops total interest faster than lowering rate alone in many cases.

Private party auto loans may lack prepayment penalty — extra principal payments still require a separate payoff schedule not shown here.

Student loan calculators in the finance section may model different repayment plans — use this for generic fixed-rate installment loans like auto and personal loans.

Gap between monthly payment and total paid summary helps compare 3-year versus 5-year terms at the same APR on the same principal.

Origination fees financed into the loan increase effective APR — this form uses nominal rate on principal only without any fee add-ons.

Limits: fixed-rate, fully amortizing loans only. No balloon payments, interest-only periods, origination fees rolled into principal, PMI, escrow for taxes and insurance, or variable rates. Not a loan offer — lenders apply credit score, debt-to-income, and product rules that change your actual rate.