What this loan calculator does
Enter how much you want to borrow, the interest rate (use the APR for the most realistic result), and the repayment term in months or years. You’ll see the fixed monthly payment, the total you’ll repay over the life of the loan, and how much of that is interest. Add an optional extra monthly payment to see how much sooner you’d be debt-free.
The payment schedule shows the split between principal and interest for every period, so you can see exactly where your money is going.
How loan payments are calculated
Most personal, auto and student loans are amortized: you pay the same amount every month, and that amount is set so the balance reaches zero exactly at the end of the term. The formula is:
Payment = P × r ÷ (1 − (1 + r)^−n)where P is the amount borrowed, r is the monthly rate (annual rate ÷ 12) and n is the number of monthly payments. For a 0% loan the payment is simply P ÷ n.
Worked example
Borrow $15,000 at 9.5% APR over 36 months:
- Monthly payment: $480.48
- Total repaid: $17,297
- Total interest: $2,297
Add $100 extra each month and the loan is gone in 30 months, with interest falling to about $1,850.
Comparing loan offers
When two lenders quote different rates and terms, the monthly payment alone can mislead you. A longer term lowers the payment but raises the total interest. Run each offer through the calculator and compare the total interest line — that’s the real price of the loan. Also check for:
- Origination fees, often 1–8% of the loan, deducted before you receive the money.
- Prepayment penalties, which can wipe out the benefit of paying early.
- Variable rates, which can rise after an introductory period.
Common loan terms
| Loan type | Typical term | Typical APR range |
|---|---|---|
| Personal loan | 2–7 years | 7%–36% |
| Auto loan | 3–7 years | 5%–15% |
| Federal student loan | 10–25 years | 5%–9% |
| Small-business term loan | 1–10 years | 7%–30% |
Rates vary widely with credit score, so use the quote you’ve actually received rather than an average.
Frequently asked questions
What's the difference between interest rate and APR?
The interest rate is what you pay to borrow the money. APR (annual percentage rate) also folds in origination fees and some other costs, so it's the better number for comparing offers. Enter the APR here to get a closer estimate of the true cost.
Why is my early payment mostly interest?
Interest is charged on the outstanding balance each month. At the start the balance is highest, so interest takes the biggest slice. As you pay down principal, interest shrinks and more of each payment reduces the balance.
Is it better to pay a loan off early?
Usually yes if the rate is high (credit cards, personal loans) and there's no prepayment penalty. For low-rate loans, you may earn more by investing the money instead. Check your loan agreement for prepayment fees before paying extra.
Does this work for student loans?
Yes, for standard fixed-rate repayment. Income-driven repayment plans and variable-rate loans change over time, so treat the result as an estimate for those.
Last updated August 26, 2026.