You are thinking about borrowing money. Maybe you are buying a $30,000 car, a $300,000 house, or planning to pay off a $5,000 credit card balance. You know the amount and the interest rate, but you have one critical question: "How much is this actually going to cost me every month?" You could try to calculate it yourself. But loans work differently. A car loan is amortized one way, a credit card minimum payment is calculated another way, and a mortgage includes extras like taxes and insurance. Doing the math in your head is nearly impossible. Or you could use a payment calculator to instantly see that your $30,000 car loan at 6% for 5 years will cost exactly $580 per month—and will cost you $4,799 in total interest if you pay it on schedule. A payment calculator computes your monthly installment for any type of loan (mortgage, auto, personal, or credit card) based on the principal, interest rate, and term. It helps you budget accurately and see the long-term cost of debt. In ...