Compound Interest Rate Calculator

Calculating Required Compound Interest Rate

When planning financial goals, you often know where you are starting (initial principal), where you want to end up (target balance), and how long you have (time period). Calculating the required interest rate helps determine which investment strategy or asset class is required to reach your target.

Formula for Interest Rate with Compounding

The standard compound interest formula is:

$$A = P \left(1 + \frac{r}{n}\right)^{nt}$$

Solving for the nominal annual interest rate ($r$):

$$r = n \left[ \left(\frac{A}{P}\right)^{\frac{1}{nt}} - 1 \right]$$

Where:

• $A$ = Final balance
• $P$ = Initial principal
• $r$ = Nominal annual interest rate
• $n$ = Compounding periods per year
• $t$ = Time in years