The operation which calculates results for the "Retirement Calculator" is based upon a joint compounded returns formula (shown below) and is built in JavaScript using functions, loops, and arithmetic operators. In addition, JavaScript uses 64-bit floating-point numbers, providing approximately 16 decimal digits of precision.

Compound Returns Formula

• A = final amount
• P = initial principal balance
• r = interest rate
• n = number of times interest applied per time period
• t = number of time periods elapsed

Read more about how continuously compounded returns are calculated here.