๐ How to Use This Compound Interest Calculator
1
Select your currency - Choose from 50+ world currencies with country flags.
2
Enter principal amount - Input your initial investment or deposit amount.
3
Add monthly contributions (optional) - Enter any regular monthly deposits.
4
Set time period & interest rate - Enter investment duration and expected annual return.
5
Choose compounding frequency - Select how often interest is compounded.
6
Click "Calculate" - Get your future value, total interest, and APY.
๐ What is Compound Interest?
Compound interest is the interest calculated on the initial principal, which also includes all of the accumulated interest from previous periods. In other words, it's "interest on interest" - this concept allows your money to grow at an accelerating rate over time.
Albert Einstein famously called compound interest the "eighth wonder of the world" and said, "He who understands it, earns it; he who doesn't, pays it."
๐งฎ Compound Interest Formula
A = P ร (1 + r/n)^(nรt)
Where:
โข A = Final amount (Future Value)
โข P = Principal amount
โข r = Annual interest rate (decimal)
โข n = Compounding periods per year
โข t = Time in years
โก The Rule of 72
The Rule of 72 is a quick way to estimate how long it takes for an investment to double at a given interest rate. Simply divide 72 by the annual interest rate. For example, at 8% interest: 72 รท 8 = 9 years to double your money.
โ Frequently Asked Questions
What is the difference between APR and APY?
APR is the simple annual interest rate. APY includes the effect of compounding. For the same rate, APY is always higher when compounding occurs more than once per year.
How does compounding frequency affect returns?
More frequent compounding leads to higher returns. Daily compounding yields slightly more than monthly, which yields more than quarterly, and so on.
Why should I include monthly contributions?
Monthly contributions can dramatically increase your final returns. Starting early and contributing consistently is one of the most effective wealth-building strategies.
What is a good rate of return?
Historical average stock market returns are around 7-10% annually. Savings accounts typically offer 1-5%. Your expected return depends on your risk tolerance.