Investment Calculator
This investment calculator projects how your money could grow over time with a starting balance, regular contributions, and a chosen annual return. Just enter your numbers in the calculator above to see your estimated future balance.
For example, $10,000 plus $500 a month at a 7% annual return grows to about $300,851 over 20 years. You put in $130,000, while compounding adds $170,851 in growth.
Investing calculators
How it works
The investment calculator above multiplies your contributions by a fixed annual return that compounds monthly. You provide a starting balance, a monthly contribution, an annual return rate, and a number of years. The tool then projects your ending balance and splits it into what you contributed versus what growth added.
Here is the key insight: in the example above, growth of $170,851 is larger than the $130,000 you contributed. Compounding means you earn returns on past returns, so over time growth can overtake your own deposits. The earlier you start, the bigger this effect becomes. This is an estimate — the calculator assumes one fixed annual return, but real markets rise and fall, so actual results will vary. Explore the compound interest calculator and investment growth calculator to go deeper.
Investment basics start with three building blocks. A stock is partial ownership in one company. An ETF holds a basket of stocks (or bonds) and trades like a single stock during market hours. An index fund tracks a benchmark like the S&P 500 and simply owns what the index owns — that is why fees are lower. Where you hold them matters too: a taxable brokerage account gives full flexibility but taxes gains each year, while a retirement account (401(k), IRA) defers or eliminates tax but locks the money until age 59½. The SEC's investor.gov guide recommends using tax-advantaged accounts first, then a brokerage for extra savings.
How to invest in stocks — a 4-step starter framework. First, open a brokerage or IRA account at a low-fee provider (no minimum, no trade commissions on stocks and ETFs). Second, buy a broad, low-cost S&P 500 or total-market index fund — one purchase gives you exposure to hundreds of companies. Third, automate contributions on payday so investing happens before you can spend the money. Fourth, ignore the daily headlines; the S&P 500 has returned about 10% a year on average since 1957 despite dozens of scary drawdowns along the way. Use the S&P 500 calculator to see what a steady contribution schedule would have produced. If you'd rather delegate the plan than DIY it, read our guide on how to choose a financial advisor before you sign anywhere.
Investment strategies worth knowing. Buy-and-hold owns the market long term and skips timing decisions. Dollar-cost averaging invests the same amount on a fixed schedule, which buys more shares when prices fall and fewer when they rise. Tax-advantaged prioritization means filling accounts in this order: employer 401(k) up to the match, then Roth or traditional IRA, then more 401(k), then a taxable brokerage. The order captures free money and tax breaks before flexibility. Once your accounts are funded, dividend-paying funds and interest-bearing accounts can become steady passive income streams that complement earned income.
Frequently asked questions
What is an investment calculator?
An investment calculator is a tool that projects how your money grows over time. You enter a starting amount, regular contributions, an annual return, and a time period. It then estimates your future balance and how much of it comes from growth versus your own deposits.
How accurate is this investment calculator?
The calculator gives an estimate, not a guarantee. It assumes one fixed annual return that compounds monthly. Real investment returns change year to year, so your actual balance could be higher or lower than the projection.
Why does growth eventually exceed my contributions?
Growth exceeds contributions because of compounding. You earn returns on your money and on past returns too. In the example above, $130,000 in deposits produced $170,851 in growth over 20 years, so growth outpaced what you put in.
Why does starting early matter so much?
Starting early matters because compounding needs time to build. The longer your money stays invested, the more returns stack on top of past returns. FINRA notes that even small investments can grow over time and benefit from compounding.
Which calculator should I use next?
Pick the tool that matches your goal. Try the compound interest calculator, the investment growth calculator, the high yield savings calculator, or the savings goal calculator. See all our free financial calculators.