ANALYSIS
Compound interest calculator
Solve for the final amount, principal, rate, or time - pick which one is unknown
How it works
Compound interest grows a principal at a given rate, compounding some number of times per year, for a number of years: A = P(1 + r/n)^(nt). Pick which one of the four values - amount, principal, rate, or time - you want solved, enter the other three, choose how often it compounds, and the calculator rearranges the formula for you.
A = P(1 + r/n)^(nt) · Not financial advice
Frequently asked questions
What is compound interest?
Compound interest is interest earned on both your original principal and on the interest already added to it, so the base it grows from gets bigger every period. A = P(1 + r/n)^(nt), where P is principal, r is the annual rate, n is how many times per year it compounds, and t is time in years.
Why does compounding frequency (monthly vs annual) matter?
The same nominal annual rate gives a higher actual return the more often it compounds, because each compounding period adds interest that then itself earns interest sooner. Monthly compounding at a given rate always beats annual compounding at the same rate - the gap is the difference between the nominal rate and the Effective Annual Rate shown below.
What is Effective Annual Rate (EAR), and how is it different from the rate I enter?
The rate you enter is the nominal annual rate - the headline number. EAR is what that rate actually works out to once compounding is applied: EAR = (1 + r/n)^n − 1. For annual compounding the two are identical; for any more frequent compounding, EAR is always slightly higher than the nominal rate.