Investment Growth Calculator
Project your investment portfolio growth with monthly contributions and a stacked area chart.
Before you calculate
Assumes end-of-month contributions and constant monthly growth. Market volatility, taxes and investment costs are excluded.
Compound Growth and Dollar-Cost Averaging
Compound growth means each year's gains also earn returns in subsequent years. Regular monthly contributions (dollar-cost averaging) smooth out market volatility and accelerate wealth accumulation, particularly over long time horizons.
Balance = P(1 + r/12)^(12t) + C × [(1 + r/12)^(12t) − 1] / (r/12)Example Scenarios
Starting Early Makes a Huge Difference
Investing $5,000 at age 25 at 8% annual return grows to over $108,000 by age 65. The same $5,000 invested at age 45 grows to only about $23,000 — less than a quarter as much. Time is the most powerful variable in compound growth.
Consistent Monthly Contributions
Contributing $300/month with $0 initial investment at 8% over 30 years yields approximately $408,000 — with only $108,000 in actual contributions. The remaining $300,000+ is pure compound growth, illustrating the power of consistent investing.
Methodology & Assumptions
Balance is calculated month-by-month: balance = balance × (1 + r/12) + monthlyContribution, where r = annualReturn/100. Yearly snapshots are captured. Total growth = finalBalance − totalContributions.
Sources & calculation notes
Maintained by MoneyCalc. Results are estimates based on the inputs and assumptions shown, not personalized financial advice or a lender quote. Default rates are examples unless a specific tax year or official table is identified.
References explain the underlying concepts or rules. They do not endorse or independently certify this implementation.
Calculations run in your browser. Some tools retain settings on this device. Displayed rounding can produce small differences from a statement or contract.