How is a loan payment calculated?
Most installment loans use an amortization formula based on the loan amount, APR, and number of monthly payments.
Loan Calculator
Estimate loan payments and see the full payoff timeline
Use this calculator for personal, auto, or student loans. Adjust the amount, APR, term, and extra payment to see the monthly payment, total interest, and amortization schedule.
Monthly payment and total interest
Extra payment savings and earlier payoff
Full amortization schedule by month
Enter loan details
Update the amount, APR, term, and extra payment to compare the monthly payment and long-term borrowing cost.
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Amortization schedule
Review payment, principal, interest, and remaining balance by month.
| Month | Year | Payment | Principal | Interest | Balance |
|---|---|---|---|---|---|
| 1 | 1 | $489.15 | $353.74 | $135.42 | $24,646.26 |
| 2 | 1 | $489.15 | $355.65 | $133.50 | $24,290.61 |
| 3 | 1 | $489.15 | $357.58 | $131.57 | $23,933.03 |
| 4 | 1 | $489.15 | $359.52 | $129.64 | $23,573.51 |
| 5 | 1 | $489.15 | $361.46 | $127.69 | $23,212.05 |
| 6 | 1 | $489.15 | $363.42 | $125.73 | $22,848.63 |
Total payments
60 months
Total interest
$4,349.18
Best for comparing terms
Try the same loan amount with different terms to see how a lower monthly payment usually increases total interest paid.
Extra payments matter
Even small extra monthly payments can reduce interest and shorten the life of the loan.
Related debt and loan pages
Loan calculator FAQ
Do extra payments help?
Yes. Extra monthly principal payments reduce the balance faster, which lowers total interest and shortens the payoff period.
What is APR?
APR is the annual percentage rate. It reflects the yearly borrowing cost and can include certain fees in addition to the interest rate.
Can I compare different loan types here?
Yes. The calculator works well for many fixed-payment personal, auto, and student loan scenarios.
Payment formula
M = P x [ r(1+r)^n ] / [ (1+r)^n - 1 ]
P is the loan amount, r is the monthly interest rate, and n is the total number of monthly payments.