When is simple interest used?

Simple interest is common for some short-term loans and certain bonds; most savings accounts, CDs, and credit cards use compound interest instead, which grows faster.

Simple Interest Calculator

Banking & Interest

Calculate simple (non-compounding) interest on a principal amount.

Display currency

Changing the display currency only changes the symbol shown — amounts aren't converted, since this tool doesn't use live exchange rates.

Principal

Annual interest rate (%)

Time (years)

Total interest

Total amount (principal + interest): $0

How this is calculated

Simple Interest = Principal × Rate × Time. Unlike compound interest, simple interest is calculated only on the original principal — it never earns interest on previously-accrued interest.

Frequently asked questions

When is simple interest used?: Simple interest is common for some short-term loans and certain bonds; most savings accounts, CDs, and credit cards use compound interest instead, which grows faster.

CD Calculator

Calculate the maturity value of a Certificate of Deposit (CD).

Savings Calculator

Project your savings account balance from an initial deposit and recurring monthly deposits.

APY Calculator

Convert a nominal interest rate into its Annual Percentage Yield (APY) based on compounding frequency.