Loan Calculator
Calculate monthly payment for any fixed-rate loan.
Understand the complete cost of a loan
Calculate payments, test extra principal, or compare two lender offers.
1Choose a calculation
2Loan information
Included in the true borrowing cost, not the monthly payment.
Change any value to see its effect immediately.
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How to calculate loan
A loan calculator turns a lump sum, an interest rate, and a repayment period into a real monthly payment number — the figure that actually determines whether a loan fits your budget. It works for personal loans, auto loans, student loans, or any fixed-rate installment loan where you borrow once and repay in equal monthly amounts.
Lenders quote rates and terms, but they rarely lead with the number that matters most day to day: what leaves your account every month. Running your own numbers before you sign lets you compare offers apples-to-apples and catch a payment that looks fine at a glance but strains your budget over years.
How the calculation works
Monthly payment = P × (r / 1200) × (1 + r/1200)^n / ((1 + r/1200)^n − 1), where P is the loan amount, r is the annual interest rate as a percentage, and n is the number of monthly payments (years × 12). This is the standard amortizing-loan formula — it produces the fixed payment that pays off both principal and interest exactly by the last payment.
Example
Borrow $15,000 at 7.5% for 4 years (48 payments): the monthly payment comes out to about $362.68. Over the full term you'd pay roughly $17,408 total — about $2,408 in interest. Stretch the same loan to 6 years instead and the payment drops to about $255/month, but total interest rises to around $3,360, because more of the balance sits at interest longer even though the rate didn't change.
Frequently asked questions
Does this include fees like origination charges or prepayment penalties?
No — this calculates principal and interest only, based on the loan amount, rate, and term you enter. Add any known fees separately when comparing total cost between lenders.
Can I use this for a loan I'm already paying off?
Yes. Enter your current remaining balance as the loan amount, your current rate, and the remaining term in years to see your existing monthly payment, or change the rate/term to model a refinance.
Why does a longer term lower my payment but raise my total cost?
Interest accrues on the remaining balance each month. A longer term keeps more balance outstanding for more months, so even though each payment is smaller, more of the loan's life is spent paying interest rather than principal.
Loan Calculator
Monthly payment = P × (r / 1200) × (1 + r/1200)^n / ((1 + r/1200)^n − 1), where P is the loan amount, r is the annual interest rate as a percentage, and n is the number of monthly payments (years × 12). This is the standard amortizing-loan formula — it produces the fixed payment that pays off both principal and interest exactly by the last payment.
Let's understand your loan result.
Calculate a result above and this guide will help you interpret it using this calculator's own formula and explanation.
Pro Tips for Loan
- Compare loans by total interest paid, not just the monthly payment — a lower payment from a longer term often costs more overall.
- Re-run the calculator with a slightly higher rate than quoted; lenders often finalize a rate after a hard credit check that can differ from the pre-qualified estimate.
- If a lender lists an origination fee, subtract it from the loan amount you actually receive but keep the full amount as what you're repaying — that gap is real cost the payment figure alone won't show.
Common Loan Mistakes to Avoid
- Comparing two loan offers by payment size alone without checking the term length — a 7-year loan will almost always beat a 3-year loan on payment size while costing far more in interest.
- Forgetting that 'years' in this calculator means the full repayment period, not a promotional or introductory rate window that resets later.
When to Use This Calculator
A loan calculator turns a lump sum, an interest rate, and a repayment period into a real monthly payment number — the figure that actually determines whether a loan fits your budget. It works for personal loans, auto loans, student loans, or any fixed-rate installment loan where you borrow once and repay in equal monthly amounts.
Lenders quote rates and terms, but they rarely lead with the number that matters most day to day: what leaves your account every month. Running your own numbers before you sign lets you compare offers apples-to-apples and catch a payment that looks fine at a glance but strains your budget over years.