Investment Calculator
Calculate how your investments grow over time with compound returns, monthly contributions, and inflation adjustment
Average historical inflation: ~3% per year
How to Use
- 1 Enter your initial investment amount (the money you start with)
- 2 Set your expected annual return rate (e.g., 7% for average stock market)
- 3 Enter monthly contributions you plan to make regularly
- 4 Choose the investment time horizon in years
- 5 Optionally adjust inflation rate to see real purchasing power
- 6 View projected growth, total returns, and year-by-year breakdown instantly
What You Get
Free online investment calculator with real-time projections. Calculates future portfolio value, total contributions, investment gains, and inflation-adjusted returns. Includes year-by-year amortization table and CSV download. Supports multiple compounding frequencies. 100% client-side — no data sent to any server.
Input: $10,000 initial + $500/month at 7% for 30 years
Output: Future value: $694,709 (contributions: $190,000, gains: $504,709)
Input: $50,000 initial + $1,000/month at 10% for 20 years
Output: Future value: $1,132,101 (contributions: $290,000, gains: $842,101)
Input: $5,000 initial at 5% for 10 years, no contributions
Output: Future value: $8,235 (interest earned: $3,235)
How much will my investment be worth in 10 years?
It depends on your initial amount, monthly contributions, and expected return rate. For example, $10,000 invested at 7% annual return with $500 monthly contributions grows to approximately $107,144 in 10 years with monthly compounding. The more you contribute monthly and the higher the return rate, the faster your investment grows thanks to compound returns.
What is a realistic return rate for investments?
The S&P 500 has returned an average of about 10% per year historically (roughly 7% after inflation). A balanced portfolio of stocks and bonds typically returns 6-8%. High-yield savings accounts offer 4-5%. Conservative bond portfolios return 3-5%. For long-term investment planning, 7% is a commonly used estimate that accounts for inflation.
How do monthly contributions affect investment growth?
Monthly contributions have an enormous impact due to compound growth. For example, $10,000 invested at 7% for 30 years without contributions grows to $81,165 with monthly compounding. Adding $500/month turns that into $694,709 — the extra $180,000 in contributions generates over $423,000 in additional gains. This is why consistent investing is the most powerful wealth-building strategy.
What is the difference between nominal and real returns?
Nominal return is the raw percentage your investment grows. Real return subtracts inflation to show actual purchasing power gain. If your investment earns 8% but inflation is 3%, your real return is approximately 5%. This calculator lets you enter an inflation rate to see both nominal and inflation-adjusted future values, giving you a realistic picture of your wealth growth.
How does compound interest work for investments?
Compound interest means you earn returns not just on your original investment, but also on all previously earned returns. With monthly compounding at 10%, a $10,000 investment earns $1,047 in year 1 (more than simple 10% because interest compounds each month). By year 30, your balance reaches $198,374 on that same initial $10,000. This exponential growth is why starting early matters so much — time is the most powerful factor.
Is this investment calculator free?
Yes, this investment calculator is 100% free with no account required. All calculations run in your browser — no data is sent to any server. There are no ads, no usage limits, and no premium features locked behind a paywall. You can also download your projection as a CSV file for further analysis.
100% client-side – your data never leaves your device