Skip to content

Investment Calculator

Project investment growth over time with monthly contributions, contribution escalation, and inflation-adjusted returns.

Investment details

Updates as you type
Mode
Mode ?
Money in
Initial investment ?
$
$0$50k$200k$500k
Monthly contribution ?
$ / mo
$0$1k$5k$10k
Growth
Annual return ?
%
0%5%10%15%20%
Investment period
years
1y10y25y50y
Adjustments (optional)
Contribution escalation ?
% / yr
0%3%6%10%
Inflation rate ?
%
0%2%5%10%
Display (optional)
Currency

Growth over time

Initial + contributions + returns, stacked
Initial investment Contributions Returns

Year-by-year schedule

Year Contributions Returns Balance Real value Composition

Formula

FV = PV ( 1 + r ) n + PMT × (1 + r)n − 1 r
FV
Future value of the investment
PV
Present value (initial investment)
PMT
Monthly contribution amount
r
Monthly return rate (annual rate ÷ 12)
n
Total number of months
Worked example — your numbers
  1. Monthly rate r =
  2. Months n =
  3. Growth factor (1 + r)n =
  4. Future value of initial =
  5. Future value of contributions =
  6. Future value FV =

Contributions are added at the start of each month and compound monthly. With escalation, the monthly amount grows by the chosen percentage at the start of each year. The real-value figures discount the nominal balance by the inflation rate so you can see what the future balance is worth in today's money.

Examples

How It Works

This calculator projects investment growth using compound returns with regular contributions. It simulates month-by-month: each month, your existing balance grows by the monthly return rate, then your contribution is added.

Contribution escalation models real-world behavior — as your income grows, you contribute more. A 3% annual escalation means if you start at $500/month, year 2 you contribute $515/month, year 3 $530.45/month, and so on. Over 20+ years, this significantly increases your total contributions and final balance.

Inflation adjustment shows what your future balance is worth in today's dollars. A portfolio worth $1,000,000 in 30 years at 3% inflation has the purchasing power of about $412,000 in today's money. This is critical for realistic planning — the nominal number is impressive but the real value is what matters for your lifestyle.

The year-by-year table breaks down each year's starting balance, contributions (escalated if applicable), investment returns, and ending balance. When inflation is included, an additional column shows the inflation-adjusted value.

Tips & Best Practices

The S&P 500 has historically returned about 10% nominal (7% after inflation) annually. Use 7% as a reasonable long-term estimate for a diversified stock portfolio.
Contribution escalation of 2-3% per year (matching typical salary increases) can add 30-50% more to your final balance over 30 years compared to flat contributions.
Always check the inflation-adjusted column for realistic planning. A million dollars in 30 years won't buy what a million buys today.
Starting early matters enormously. $500/month from age 25 to 65 at 7% yields ~$1.2M. Starting at 35 yields only ~$567K — half the result for only 10 fewer years.

Frequently Asked Questions

What annual return should I use?

For a diversified stock portfolio: 7-10% nominal. For a balanced stock/bond portfolio: 5-7%. For bonds only: 3-5%. These are long-term historical averages — actual returns vary significantly year to year. Use the lower end for conservative planning.

Escalation increases your monthly contribution by a percentage each year. Starting at $500/month with 3% escalation: year 2 = $515, year 3 = $530.45, year 10 = $652.64. This models real-world salary growth — as you earn more, you invest more.

Inflation erodes purchasing power. If your portfolio grows to $2M in 30 years but prices have tripled (3% inflation), that $2M only buys what $824K buys today. The inflation-adjusted column shows real purchasing power, which is what actually determines your future lifestyle.

This calculator adds contribution escalation (increasing contributions over time) and inflation adjustment — features specifically designed for long-term investment planning. The compound interest calculator focuses on the mathematical formula with various compounding frequencies.