About the Loan Calculator
This loan calculator works for almost any fixed-rate installment loan: personal loans, auto loans, business term loans, equipment finance, home improvement loans and private student loans. Enter how much you are borrowing, the interest rate and the term, choose how often you pay, and it returns the regular payment, the total interest you will pay and the full cost of the loan.
You can also add an extra amount to every payment to see how much faster the loan is paid off and how much interest you save. The chart shows the balance falling and interest accumulating year by year, and the table gives a yearly amortization schedule you can compare against a lender’s disclosure.
Interest is charged per payment period at the annual rate divided by the number of payments per year, which is how most simple installment loans work. For mortgages with taxes and insurance, or loans with upfront fees, use the dedicated mortgage or APR calculators linked below.
With the default inputs, the payment per period is $500.95. Change any value above to recalculate instantly.
How to use the loan calculator
- 1Enter the amount you want to borrow.
- 2Enter the annual interest rate and the loan term in years.
- 3Choose how often you will make payments.
- 4Optionally add an extra amount per payment to see the time and interest saved.
- 5Review the payment, total interest and the yearly amortization table.
Formula and method
The payment is the level amount that repays the principal P plus interest over n equal periods. With k payments a year, the periodic rate r is the annual rate divided by k. Each period, interest = balance × r and the rest of the payment reduces principal, so the schedule is built one period at a time.
Extra payments are applied straight to principal, which lowers every future interest charge and ends the loan early; the regular payment stays the same. If the rate is 0%, the payment is simply P ÷ n. Totals are rounded for display only.
- PMT
- Regular payment per period
- P
- Loan principal
- r
- Interest rate per payment period
- n
- Total number of payments
- k
- Payments per year (12 monthly, 26 biweekly, 52 weekly…)
Worked examples
$25,000 at 7.5% for 5 years, monthly
A $25,000 loan at 7.5% over 60 months has a payment of $500.95. Multiply by 60 and you repay $30,057 in total, so interest costs about $5,057.
$10,000 over 3 years, paid biweekly
With 26 payments a year the periodic rate is 9% ÷ 26 and there are 78 payments. Each biweekly payment is $146.51 and total interest is about $1,428.
Adding $100 a month to a $25,000 loan
Paying $600.95 instead of $500.95 each month clears the $25,000 loan in 49 payments instead of 60 and cuts interest from about $5,057 to about $4,043 — a saving of roughly $1,014.
Frequently asked questions
How is a loan payment calculated?+
Lenders use the amortization formula PMT = P × r(1+r)^n ÷ ((1+r)^n − 1), where P is the amount borrowed, r the interest rate per period and n the number of payments. The result is a level payment that repays the loan exactly by the final period.
Do biweekly payments save money?+
Paying half the monthly payment every two weeks gives 26 half-payments, or 13 full payments a year, which pays the loan off faster and saves interest. If the lender simply recalculates a true biweekly payment on the same term, as this calculator does, the saving is small.
What happens if I pay extra on my loan?+
Extra payments go to principal (confirm this with your lender), so the balance falls faster, less interest accrues each period and the loan ends early. The earlier in the term you pay extra, the more interest you save.
Why do I pay more interest at the start of a loan?+
Interest is charged on the outstanding balance. At the start the balance is at its highest, so the interest portion of each payment is largest; as principal is repaid the interest portion shrinks.
Does this include fees or insurance?+
No. It calculates principal and interest only. Origination fees raise the true cost and are captured by APR; use the APR calculator to include them, or the mortgage calculator for taxes, insurance and PMI.
Results are estimates for educational purposes and are not financial advice. Rates, fees and terms vary — confirm with your lender or a licensed advisor before making decisions.