Investment Calculator
Compound interest and ROI calculator for long-term investment planning.
Everyday examples
🏖️ Retirement Planning
See how much your 401(k) or IRA could grow over 20-30 years with consistent monthly contributions and a mix of stocks and bonds.
🏡 Saving for a House
Plan your path to a down payment. Find out how long it will take to reach your goal using a high-yield savings account.
🎓 College Fund
Calculate the potential growth of a 529 plan or similar education savings account from your child's birth to age 18.
📈 Crypto & Stocks
Model the extreme scenarios of high-risk assets. See the impact of high volatility by playing with larger percentage gains (or losses).
How it works
Compound interest is the interest on savings calculated on both the initial principal and the accumulated interest from previous periods.
How to use the calculator
Simply enter your initial investment, monthly contribution, expected annual return rate, and the number of years you plan to invest.
- Enter initial investment amount.
- Add your estimated monthly contribution.
- Input expected annual return rate (%).
- Input the duration (Years) and click calculate.
Frequently Asked Questions
Common questions about the Investment Calculator.
Frequently asked questions
What is Compound Interest?
Compound interest is the interest on savings calculated on both the initial principal and the accumulated interest from previous periods. Over time, it creates a "snowball effect", accelerating wealth growth exponentially rather than linearly.
What is realistically a "good" interest rate?
Historically, the stock market (like the S&P 500) has returned roughly 7-10% annually on average before inflation. Bonds generally yield 3-5%, while high-yield savings accounts might yield 1-4%. For a balanced, long-term portfolio, using a 6% to 8% assumed rate of return is standard practice.
Does exactly when I compound matter?
Yes. Compounding monthly generates slightly more interest than compounding annually because the interest is added to your balance sooner, allowing it to earn its own interest.