Simple Investment Calculator: Growth, ROI, And Stock Profit

Enter a starting amount, a monthly contribution, the number of years, and an expected annual return. The calculator uses compound interest to grow the balance each month and shows the ending balance, how much you contributed, how much came from growth, and what the total is worth in today’s dollars. To see how inflation has changed prices in past years, try our inflation calculator.

A monthly contribution works best when it happens without you thinking about it. An automatic investment app or a payroll deduction into your workplace retirement plan turns the number you enter here into a habit. Investing the same amount on a schedule is called dollar-cost averaging, and it keeps you buying through both up and down markets.

Open More Options to raise your contribution each year or change the inflation rate. A 3% yearly increase mirrors a typical raise, and you can keep raising it until you reach the annual 401(k) contribution limit. The chart splits each year into contributions and growth, and the year-by-year table lists the same numbers so you can see when growth starts to outrun your deposits.

The growth tab also shows the cost of waiting. With the default inputs, starting five years later leaves you with $162,036 instead of $241,503, even though you would have put in only $12,000 less.

The ROI And Stock Profit tab measures what an investment already earned. Choose Dollar Amounts for any investment, such as a mutual fund or ETF, a real estate investment, or a crypto position like XRP. Choose Stock Shares to enter a share count with a buy price and a sell price.

Add any dividends you received in cash, the fees you paid, and how long you held the investment. If you used dividend reinvestment, those dividends already show up in the ending value, so leave the dividend box at $0. Brokers that let you trade stocks for free leave nothing to enter in the fees box.

The calculator returns total profit, ROI, annualized return, and the total you got back. Profit is shown before taxes, so run the gain through our capital gains tax calculator to see what you keep.

Here is an example for someone learning how to invest in stocks. You buy 20 shares at $50 and sell them three years later at $65. Your profit is $300, your ROI is 30%, and your annualized return is 9.1% a year.

Return on investment equals your profit divided by your total cost. Profit is the ending value plus any dividends, minus what you paid and any fees. Written out, it looks like this:

ROI = (Ending Value + Dividends − Cost − Fees) ÷ (Cost + Fees)

An investment that cost $5,000 and is now worth $7,500 has a $2,500 profit and a 50% ROI. Fees count against you twice: they lower the profit and raise the cost basis.

Total Return Vs. Annualized Return

Annualized return, also called the compound annual growth rate (CAGR), converts a total gain into a yearly rate. The formula is (Ending Value ÷ Cost) raised to the power of 1 ÷ Years, minus 1.

The $5,000-to-$7,500 investment above gained 50% over five years, which works out to 8.4% a year. The stock example gained 30% over three years, or 9.1% a year. The smaller total gain was the better investment on a yearly basis, and only the annualized rate shows that.

Annualizing a gain held less than a year can make a short-term win look enormous. For holds under a year, the total return is the more honest number.

For long-term planning with a stock-heavy portfolio, 6% to 7% is a reasonable assumption. It sits below the stock market’s long-run average to leave room for fees, inflation surprises, and bad decades. Use 4% for a portfolio that holds mostly bonds rather than stocks, or cash.

Historical return data from NYU Stern professor Aswath Damodaran shows the S&P 500, with dividends reinvested, returning about 10% a year on average from 1928 through 2025. That average hides a lot of market volatility: the index lost money in 26 of those 98 years, including a 43.8% drop in 1931.

Fund costs come straight out of your return. A fund with a 1% expense ratio turns a 7% market return into roughly 6% for you, which is why low-cost index funds are the default choice for most long-term investors.

Time in the market does more work than almost any return assumption. You also have to remember that time is the only thing working against humans, as we do have a limited lifespan.

At 7%, investing $300 a month from age 22 to 62 builds about $741,000 from $144,000 in deposits. Starting the same plan at 32 builds about $351,000 from $108,000 in deposits.

The 10-year delay costs about $390,000 even though the late starter contributed only $36,000 less. The early years matter so much because their growth has the longest time to compound. For age-by-age targets, see how much you need to save each month to reach $1 million.

Simple interest pays only on the original amount. Compound interest pays on the original amount plus all the growth it has already earned. $10,000 earning 7% simple interest for 30 years becomes $31,000. Compounded yearly at the same rate, it becomes $76,123.

Stocks and funds compound when you leave dividends and gains invested. Some bonds and CDs pay interest out instead, which behaves like simple interest unless you reinvest the payments yourself. This calculator assumes everything stays invested.

The calculator uses an average annual return, which means one steady rate applied to every year of your plan. Average annual return is the yearly rate that, earned every single year, would turn your starting amount into your ending amount. Real markets move in uneven steps, so your actual balance will land above or below the projection depending on when the good and bad years arrive.

The 10% S&P 500 figure on this page is that kind of compounded average. A simple average of each year’s return since 1928 comes out higher, close to 12%, because losses hurt more than gains of the same size help. A 40% drop takes a 67% gain just to get back to even.

Taxes and fund fees are not included either. Investing through a Roth IRA lets qualified withdrawals come out tax-free, which keeps more of the growth this calculator shows.

What Is A Good Return On Investment?

A good return beats inflation after fees and fits the risk you took. A broad stock index fund has averaged about 10% a year over the long run, so a stock pick that trails that average for years carried extra risk without the extra reward. Cash in a high-yield savings account earns less but does not lose value.

How Do I Calculate Profit On A Stock?

Subtract the buy price from the sell price, multiply by the number of shares, add any dividends you kept, and subtract trading fees. 20 shares bought at $50 and sold at $65 earn a $300 profit before fees. The Stock Shares mode in the calculator above does this math for you.

How Long Does It Take To Double My Money?

Divide 72 by your annual return to estimate the years needed to double your money. At 7%, the Rule of 72 gives about 10.3 years, close to the exact answer of 10.2 years. At 10%, money doubles in about 7.2 years.

Does This Calculator Include Taxes?

No, every result is before taxes. In a taxable account, the IRS taxes gains on investments held one year or less at ordinary income rates. Gains on investments held longer than a year get lower long-term capital gains rates of 0%, 15%, or 20%.

Is Annualized Return The Same As CAGR?

Yes. Annualized return and compound annual growth rate (CAGR) both describe the steady yearly rate that turns your starting amount into your ending amount. The ROI tab shows it as Annualized Return.