Investment Calculator
Free investment calculator — project portfolio growth with contributions, dividends, and inflation adjustments. See the impact of different risk profiles and time horizons.
Portfolio Value
$0
Total Return
0%
Adjusted for Inflation
$0
$
$0$1M
$
$0$10K
%
1%25%
years
1 yr40 yrs
%
0%10%
Growth Projection
Formula Used
Portfolio Value at Year t:
V_t = V_(t-1) × (1 + g) + C × (1 + g/2)
Inflation-Adjusted Value:
Real V_t = V_t / (1 + i)^t
Where:
g = Expected nominal annual return
C = Annual contribution
i = Inflation rate
How This Investment Calculator Works
This calculator projects portfolio growth using compound returns with regular contributions, adjusted for inflation so you can see the real purchasing power of your future wealth.
Real vs. Nominal Returns
- Nominal return: What you see on paper — e.g., "10% average S&P 500 return"
- Real return: After inflation — at 3% inflation, that 10% becomes ~7% in today's dollars
- Why it matters: $1M in 20 years buys significantly less than $1M today
The chart shows both your contributions (what you actually put in) and your investment growth (the compounding effect), giving you a clear picture of how much is "your money" vs. "market returns."
How to Use This Calculator
Step-by-Step Instructions
- Initial Investment: Enter the amount you already have invested. This could be your current brokerage account balance, retirement account value, or any lump sum you're starting with. The slider goes up to $1 million, or you can type any amount directly.
- Monthly Contribution: Set how much you plan to add each month. This is the key driver of long-term growth — even small amounts compound dramatically over decades. The default of $500/month reflects a common starting point for new investors.
- Expected Annual Return: This is your estimated yearly return before inflation. The default 10% reflects the long-term S&P 500 average. Be conservative — many advisors suggest using 7-8% for planning purposes. Adjust based on your actual portfolio composition.
- Time Horizon: How many years you plan to stay invested. Longer horizons dramatically amplify compound growth. Bumping this from 10 to 30 years can multiply your final balance several times over.
- Inflation Rate: The long-term US average is roughly 3%. This adjusts your final portfolio value into today's dollars so you can understand what your future wealth will actually buy.
Example Scenario
Say you're 30 years old with $50,000 already saved. You plan to invest $500/month, expect 10% annual returns, and have a 20-year time horizon. With 3% inflation, the calculator shows your portfolio growing to roughly $730,000. Your total contributions are $170,000, meaning over $560,000 comes from investment growth alone. After adjusting for inflation, that $730K has the purchasing power of about $404,000 in today's dollars — still a substantial gain, but it underscores why inflation matters.
What the Results Mean
- Portfolio Value: The projected total at the end of your time horizon, including both your contributions and all investment returns (nominal).
- Total Return: The percentage gain above what you contributed. A 300% total return means your money more than tripled.
- Adjusted for Inflation: What your future portfolio is worth in today's purchasing power. This is often the most sobering number — and the most important one for realistic planning.
- Growth Projection Chart: The stacked bar chart separates your contributions (blue) from investment growth (green), showing you exactly how much of your wealth came from disciplined saving vs. market returns.
Frequently Asked Questions
How much will my investments be worth in the future?
Your investment future value depends on your initial investment, ongoing contributions, expected rate of return, and time horizon. Using compound growth, even modest investments can grow significantly over decades. Use CalcDeck's free investment calculator to project your portfolio value based on your specific inputs — adjust the contribution amount, return rate, and time period to see different scenarios.
What is dollar-cost averaging and why does it matter?
Dollar-cost averaging (DCA) is investing a fixed dollar amount at regular intervals, regardless of market conditions. This strategy buys more shares when prices are low and fewer when prices are high, lowering your average cost per share over time. DCA removes the pressure of timing the market and is particularly effective for long-term investors. CalcDeck's investment calculator models regular contributions, which is exactly how DCA works in practice.
What's the average stock market return over the long term?
The S&P 500 has returned approximately 10% annually on average over the past century before inflation (about 7% after inflation). However, returns vary dramatically year to year — some years gain 30%, others lose 20%. For long-term planning (10+ years), most advisors use 6-8% as a conservative estimate. CalcDeck's investment calculator lets you adjust the expected return to model conservative, moderate, and optimistic scenarios.
How do fees affect my investment returns?
Investment fees compound against you — a 1% annual fee on a $100,000 portfolio earning 7% costs over $30,000 in lost returns over 30 years compared to a 0.1% fee. This is why low-cost index funds often outperform actively managed funds over the long term. When projecting your investment growth, use a return rate net of fees, or use CalcDeck's calculator to model slightly different return rates to account for fee drag.
What's the difference between stocks, bonds, and ETFs?
Stocks represent ownership in individual companies — high growth potential but volatile. Bonds are loans to governments or corporations — lower returns but more stable. ETFs (Exchange-Traded Funds) are baskets of stocks or bonds that trade like stocks, offering instant diversification at low cost. A balanced portfolio typically mixes all three based on your age and risk tolerance. CalcDeck's investment calculator works for any asset type — just adjust your expected return rate accordingly.
How much should I invest vs. keep in savings?
Keep 3-6 months of living expenses in a high-yield savings account for emergencies. Invest everything beyond that for goals 5+ years away. Money you'll need sooner (down payment in 2 years, tuition next year) should stay in safe, liquid accounts — not the stock market. The right split depends on your timeline and risk tolerance. CalcDeck's calculator helps you project how invested money grows, making the case for putting excess savings to work.