Compound Interest Calculator
Project your investment's future value. See how your savings grow over time with interest and regular contributions.
The magic of compounding
Compound interest is often called the "eighth wonder of the world" because of its ability to multiply wealth over long periods. Unlike simple interest, which is only paid on the original amount, compound interest is earned on both your principal and the interest you've already accumulated.
How variables affect your wealth
- Time: The most powerful factor. Starting just a few years earlier can result in significantly larger final balances.
- Frequency: The more often interest is added back to your balance, the faster your money earns interest on itself.
- Contributions: Regular monthly deposits act as a constant fuel source for the compounding engine.
Frequently asked questions
What is compound interest?
Compound interest is interest calculated on the initial principal, which also includes all of the accumulated interest from previous periods on a deposit or loan.
How often should interest be compounded?
The more frequently interest is compounded, the faster your investment grows. Common frequencies include monthly, quarterly, and annually. This calculator lets you toggle between them.
What is the formula for compound interest?
The standard formula is A = P(1 + r/n)^(nt), where A is the final amount, P is the principal, r is the annual interest rate, n is the compounding frequency, and t is the time in years.
Can I include monthly contributions?
Yes. This calculator accounts for regular monthly contributions added to your principal, showing how consistent saving accelerates your wealth growth.