Calculate your monthly loan payment, total interest, and full payment schedule for any fixed-rate loan. Free loan payment calculator for personal, auto, student, and business loans.
A loan calculator works out your fixed monthly payment from the amount borrowed, the annual interest rate and the loan term in months or years. It also shows the total interest you will pay and the full repayment amount over the life of the loan.
Personal, auto, student & business loans
This loan payment calculator uses the standard amortization formula to compute your fixed monthly payment based on loan amount, interest rate, and term. Enter any fixed-rate loan — personal loan, auto loan, student loan, or business loan — and instantly see how much of each payment goes to principal versus interest, plus your total interest cost over the life of the loan. A $25,000 personal loan at 8.5% for 3 years comes out to $789/month with about $3,400 in total interest. Extend the same loan to 5 years and the monthly payment drops to $513 — but total interest climbs to nearly $5,800. The loan amortization schedule shows this trade-off payment by payment.
In 2026, loan interest rates vary widely by type and credit score. Auto loans for new vehicles average 6%–9% for excellent credit; personal loans run 8%–25% depending on creditworthiness; federal student loan rates are set annually by Congress, ranging from 6.53% for undergrad to 9.08% for Grad PLUS loans in 2024–2025. Business loans from traditional banks often require strong revenue history and may carry rates from 7% to 15%+. Regardless of loan type, the monthly payment formula is the same — and this calculator gives you the exact number before you walk into a bank or sign an online application.
Average personal loan APR: 8%–12% for excellent credit (760+ FICO), 15%–25% for fair credit. Online lenders like SoFi, LightStream, and Marcus often beat traditional banks on rates for well-qualified borrowers.
New car rates: 5.5%–8.5% for good-excellent credit. Used car rates run 1%–3% higher. Credit unions consistently offer below-average rates — check yours before visiting the dealership's finance office.
Shorter terms mean higher monthly payments but dramatically less total interest. A $20,000 loan at 9%: 3-year term = $636/mo, $2,900 interest. 5-year term = $415/mo, $4,900 interest — $2,000 more in interest for $221 less per month.
On a $30,000 loan over 5 years: 7% APR costs $5,440 in interest; 12% APR costs $9,720 — a $4,280 difference. Getting pre-approved at multiple lenders before accepting a rate almost always pays off.
Every instalment loan — mortgage, car, personal, student — is solved by the same amortization formula, which finds the constant payment that retires a principal over a fixed term at a fixed rate. What differs between loan types is not the mathematics but the term and the rate, and those two inputs behave very differently. Rate affects total interest roughly proportionally; term affects it far more than intuition suggests, because a longer term keeps a large balance outstanding for longer and interest is charged on the balance, not on the original amount.
M = P × [ i(1 + i)^n ] ÷ [ (1 + i)^n − 1 ]Total interest = (M × n) − PSolve for P: P = M × [ (1 + i)^n − 1 ] ÷ [ i(1 + i)^n ]where:
Assumptions: Assumes a fixed rate, level payments and no fees. Origination fees raise the effective cost above the nominal rate — compare APR rather than rate when fees differ between offers.
Hold the amount and rate constant and vary only the term, to isolate what term costs.
Result3 yr $800.82/mo ($3,830 interest) — 7 yr $408.60/mo ($9,322 interest)
This asymmetry is the single most useful thing to understand about borrowing. Lenders advertise the monthly payment because a longer term always makes it look better, while the total cost moves sharply the other way. Choose the shortest term whose payment you can comfortably sustain.