Compound interest is a financial term that refers to the interest earned on both the principal amount and the accumulated interest. Its spelling in IPA is /ˈkɒmpaʊnd ˈɪntrəst/. The word ‘compound’ is pronounced with stress on the first syllable, where the ‘o’ is pronounced like ‘ah’ and ‘u’ like ‘uh’, followed by an unstressed middle ‘u’ that sounds like ‘uh’, and stress on the final syllable. Similarly, ‘interest’ is pronounced like ‘IN-truhst’ with stress on the first syllable and a short ‘i’ sound followed by an unstressed ‘t-r’.
Compound interest is a financial concept that refers to the interest earned or charged on a principal amount, which then accumulates and earns additional interest over time. It is a way of calculating interest that takes into consideration not only the initial amount of money, or principal, but also the interest accumulated on that principal over time.
When interest is compounded, it is added to the initial principal amount, and then continues to earn interest on both the principal and the accumulated interest. This results in a compounding effect, where the interest earned in each period is higher than the previous one. As time progresses, the interest begins to earn interest itself, leading to exponential growth of the investment or debt.
The compound interest formula takes into account the interest rate, the number of compounding periods, and the initial principal. It allows individuals to determine the future value of an investment or the total amount owed on a loan after a certain period of time.
Compound interest is commonly used in various financial instruments, such as savings accounts, certificates of deposit, and loans. It incentivizes individuals to save or invest their money for a longer duration, as the interest earned over time can significantly enhance their overall returns. Conversely, compound interest on loans can lead to exponential growth in the amount owed if the interest is not regularly paid off.
The word "compound" in "compound interest" comes from the Latin word "componere", which means "to put together" or "to combine". The term "interest" has roots in the Latin word "interesse", meaning "to be of importance" or "to be of concern".
The concept of compound interest originated in ancient Mesopotamia and was later developed by various civilizations including the Greeks and Romans. The term "compound interest" itself gained usage in the 17th century and has been widely used since then to describe the process of adding interest to an initial sum of money and then reinvesting the total amount earned.
The term "compound" is used because in compound interest, the interest is added to the principal sum and then, in subsequent periods, further interest is calculated based on the new total (principal + previously accumulated interest). This compounding effect allows the investment to grow at an accelerated rate over time.