Loan Calculator
Monthly payment, interest and amortization table.
■ Principal ■ Interest
Amortization schedule
About this tool
Loan Calculator works out the fixed monthly payment for a loan from the amount, interest rate and term. It lists every payment in an amortization schedule and shows how much interest and time you save by paying extra each month.
How to use Loan Calculator
- Enter the loan amount, interest rate and term.
- Add an optional extra monthly payment.
- Read the payment, totals and schedule.
Questions people ask
What formula is used for the monthly payment?
M = P × r × (1 + r)^n ÷ ((1 + r)^n − 1), where P is the loan amount, r is the yearly rate ÷ 12 and n is the number of months. A 200,000 loan at 6% for 30 years gives r = 0.005, n = 360 and M = 1,199.10.
How do extra payments save money?
Each month, interest = remaining balance × r. Any extra amount goes straight to the balance, so next month's interest is smaller and the loan ends sooner. On the 200,000 example, 100 extra a month saves about 49,000 in interest and ends the loan 5 years and 5 months early. Check that your lender has no prepayment penalty.
Why is most of the early payment interest?
Interest is charged on the balance, which is highest at the start. In month 1 of the example, interest is 200,000 × 0.005 = 1,000 and only 199.10 reduces the balance. The split shifts toward principal over time.