Interest is the cost of using money. The interest rate paid is usually expressed in annual terms though money market instruments may have a shorter term than one year. An interest rate is determined by dividing the amount of interest paid by the principal amount borrowed. For example, if a $1000 bond pays $85 in interest for one year, the annual interest rate is 8.5 percent. In the U.S. some interest-bearing bonds, such as municipals, entitle the bearer to an exemption from certain taxes on interest income. The interest paid by a company on its outstanding debt as well as the interest paid by a homeowner on his/her mortgage, is deductible from income as an expense and so can reduce the amount of tax owed.
　　利息是使用貨幣的成本。利率的支付形式通常以年為期限，雖然金融市場票據(jù)會(huì)有一個(gè)更短的時(shí)間。利率的制定取決于借款本金所劃分的利息。舉個(gè)例子，如果1,000美元的債券每年支付85美元的利息，那么年利率就是8.5%。美國有一些有息債券，如政府債券，它允許持有人在利息收益上有一定的免稅。公司未償債務(wù)和按揭住房的屋主需支付的利息可以作為一項(xiàng)費(fèi)用減少他們的應(yīng)交稅金。