“利息”一词常见的英文表达是interest，“利率”一词常见的英文表达是rate。

“单利”是指一笔资金无论存期多长，只有本金计取利息，而以前各期利息在下一个利息周期内不计算利息的计息方法。

“单利”对应的英文表达是simple interest，英文释义如下：

Simple interest is an interest charge that borrowers pay lenders for a loan. It is calculated using the principal only and does not include compounding interest. Simple interest relates not just to certain loans. It's also the type of interest that banks pay customers on their savings accounts.

“复利”是指在计算利息时，某一计息周期的利息是由本金加上先前周期所积累利息总额来计算的计息方式，也即通常所说的"利生利"，"利滚利"。

“复利”对应的英文表达是compound interest，英文释义如下：

Compound interest accrues and is added to the accumulated interest of previous periods; it includes interest on interest, in other words.

可参考双语例句：

此外，除非合同中另有明确约定，仲裁员无权裁决支付高于当 时实行的伦敦银行同业拆放利率的利息，并且任何此种利息应只是单利。

In addition, unless otherwise expressly provided in the contract, the arbitrator shall have no authority to award interest in excess of the London Inter-Bank Offered Rate (“LIBOR”) then prevailing, and any such interest shall be simple interest only.

复利的作用常常被过分夸大，尤其是人们试图向我们推销理财产品时。

Compound interest can be overhyped, usually by people trying to sell us pensions.

资金等值计算基本方法有单利法和复利法两种。

In equivalence of the fund the basic calculating method has laws of simple interest and compound interest law.