Investment Calculator

Estimate how your investment can grow over time with compound growth and regular monthly contributions.

Changing currency changes the symbol only. It does not convert the amount.

Starting balance

$

Amount added every month

$

Estimated yearly growth percentage

%

Years to invest

years

Frequency

What is an investment calculator?

An investment calculator is a financial tool that helps you estimate the future value of your investments. By factoring in your starting balance, regular contributions, expected rate of return, and the power of compound growth, it provides a clear projection of your potential wealth over time.

Whether you are planning for retirement, saving for a major purchase, or simply looking to grow your wealth, this calculator helps you set realistic goals and understand the long-term impact of your investment decisions.

How to use this calculator

1
Initial Investment

Enter the lump sum amount you are starting with today.

2
Monthly Contribution

Input the amount you plan to invest consistently every month.

3
Expected Return

Set a realistic annual growth rate based on your investment strategy.

4
Investment Term

Choose how many years you plan to keep your money invested.

What is compound growth?

Compound growth is the process where the returns on your investment begin to generate their own returns. It is often referred to as "interest on interest" and is the primary engine of long-term wealth creation.

Because of compounding, the earlier you start investing, the less money you actually need to contribute out of pocket to reach your financial goals. Time is your greatest asset in investing.

How monthly contributions affect investment growth

Consistently adding money to your investments—often called dollar-cost averaging—accelerates your wealth building. Regular contributions continuously increase the principal balance that generates returns.

Even modest monthly contributions can drastically increase your final portfolio value over a 10, 20, or 30-year period, smoothing out market volatility along the way.

Example investment calculation

Imagine you start with an initial investment of $5,000 and commit to investing $500 every month.

  • You invest in a diversified portfolio with an expected 8% annual return.
  • You continue this strategy for 20 years.
  • Your total out-of-pocket contributions equal $125,000.

How expected return affects final value

Thanks to the 8% compound growth, your final portfolio value would be approximately $318,389. You earned over $193,000 in pure investment returns! If the return were only 4%, your final value would be significantly lower, highlighting the importance of asset allocation.

Common investment mistakes

Waiting too long to start investing, missing out on years of compound growth.

Trying to time the market instead of consistently investing every month.

Using overly optimistic expected return rates (e.g., 15-20%) for long-term planning.

Panic selling during temporary market downturns.

Ignoring the impact of high investment fees and taxes on long-term returns.

Frequently Asked Questions

Related Calculators

Vehicle Finance Calculator

Calculate payments for your next car.

Loan Calculator

Calculate payments for personal loans.

Mortgage Calculator

Estimate your monthly home payments.

Budget Calculator

Plan your monthly income and expenses.

Savings Calculator

See how your money grows over time.

Net Worth Calculator

Track your assets minus liabilities.

Investment projection limitations and references

The projection assumes a constant annual return converted to an equivalent monthly rate and end-of-month contributions. It does not model market volatility, sequence risk, losses, fees, tax or inflation and does not guarantee an outcome or provide personalized advice. Changing currency changes the symbol only; it does not convert the inputs.

Authoritative references

Calculation method, worked example and reference

What this calculator does and formula: Compound future value without contributions is FV = P(1+r/n)^(nt). Contributions are accumulated using the selected timing and compounding period.

Variables and units: Enter values in the units named by the controls. The calculator converts through its internal base unit or applies the displayed geometric or financial relationship before rounding the presented result.

Verified worked example: 10,000 invested for 10 years at 8% compounded annually grows to 21,589.25 before fees and tax.

Result interpretation, assumptions and practical limits: Returns are assumptions, not forecasts. Inflation, volatility, fees, tax and contribution timing materially affect results.

Professional check: Treat the result as a planning estimate. Where safety, regulated work, contracts or significant money are involved, verify inputs and the result with the governing standard, manufacturer data and an appropriately qualified professional.

Authoritative reference

SEC compound-interest calculator