Interest

thumb|right|upright=1.3|A bank sign in Malawi listing the interest rates for deposit accounts at the institution and the base rate for lending money to its customers In finance and economics, interest is payment from a debtor or deposit-taking financial institution to a lender or depositor of an amount above repayment of the principal sum (that is, the amount borrowed), at a particular rate. It is distinct from a fee which the borrower may pay to the lender or some third party. It is also distinct from dividend which is paid by a company to its shareholders (owners) from its profit or reserve,

when interest is added to the principal of a deposit or loan, so that, from that moment on, the interest that has been added also earns interest

Riba (, or , ) is an Arabic word used in Islamic law and roughly translated as "usury": unjust, exploitative gains made in trade or business (especially banking). Riba is mentioned and condemned in several different verses in the Qur'an (3:130, 4:161, 30:39, and the commonly referenced 2:275-2:280). It is also mentioned in many hadith (reports of the life of Muhammad).

conjecture that there is greater benefit to receiving a sum of money now rather than later

methods of estimating the doubling time of an investment

correlation between the rate of interest and the rate of inflation

encyclical

money earned on an investment with interest

Financial ratio

punitive interest given to borrowers

financial measurement of pre-paid interest

book by Eugen von Böhm-Bawerk