Investment Calculator - Compound Growth & Returns
Project investment growth from a starting amount, return rate, compounding, and recurring contributions.
Enter an initial investment, annual return, investment period, compounding schedule, and optional recurring contribution.
Investment Calculator - Compound Growth & Returns
Project investment growth from a starting amount, return rate, compounding, and recurring contributions.
About Compound Investment Growth
An investment calculator compounds a starting balance, then adds the future value of recurring contributions. That combination is the usual planning picture for a brokerage account, a savings plan, or a simplified retirement projection: money already invested keeps earning, and new deposits keep arriving on a schedule.
The investment calculator compounds the initial amount at the annual rate for the chosen compounding frequency: initial × (1 + rate ÷ n)^(n × years). Recurring contributions are treated as end-of-period deposits. Their future value is contribution × ((1 + rate ÷ contribution frequency)^(contribution frequency × years) − 1) ÷ (rate ÷ contribution frequency). Total deposits equal the initial amount plus every contribution. Investment growth is future value minus those deposits, and return on investment is growth divided by total deposits.
A $10,000 start, 7% annual return, 10 years, and $100 each month, with monthly compounding and monthly contributions, grows to about $37,405.09. Without additions, $5,000 at 5% for five years, compounded monthly, reaches about $6,416.79. Longer horizons amplify contributions: $20,000 plus $500 monthly at 8% for 20 years projects about $393,046.26 under the same end-of-period convention.
The model uses a constant rate and does not apply taxes, account fees, or contribution limits. Real markets vary year to year; a 7% average is not a 7% path. Contribution frequency and compounding frequency are separate controls, so a monthly deposit with annual compounding is allowed even though a bank might credit interest on a different schedule. Use the investment calculator to size a savings rate or to compare “start now versus start later,” then verify product fees and tax wrappers before you commit cash. Sequence-of-returns risk still matters: earning the average rate every year is not the same as earning that average after a large early loss. Revisit the rate after fees and inflation if the projection is meant to support a spending plan rather than a headline future-value number.
Investment Calculator Worked Examples
Use these worked scenarios to check inputs and understand how the estimate responds.
| Inputs | Result | Interpretation |
|---|---|---|
| $10,000 initial, 7% annual return, 10 years, $100 monthly | About $37,405.09 future value | Monthly additions increase both deposits and compounding. |
| $5,000 initial, 5% annual return, 5 years, no additions | About $6,416.79 future value | The result is the starting amount compounded monthly. |
| $20,000 initial, 8% annual return, 20 years, $500 monthly | About $393,046.26 future value | Longer horizons amplify recurring contributions. |
How to Project Compound Investment Growth
- Enter the initial investment, annual return, and number of years.
- Choose compounding frequency and, if you invest on a schedule, the contribution amount and contribution frequency.
- Select Calculate to see projected future value, total contributions, growth, and return on investment.
- Set contributions to zero or change the rate to compare a lump-sum path with a savings plan.
Investment Calculator FAQ
Are contributions added at the beginning or the end of each period?
The investment calculator treats contributions as end-of-period deposits. Beginning-of-period deposits would earn one extra period of interest and produce a slightly higher future value.
What compounding frequency should I choose?
Match the account if you know it: many savings accounts compound daily or monthly, while some bonds pay semi-annually. If you are modeling a long-run market return, monthly compounding is a common planning default.
Does the investment calculator include taxes or fees?
No. The rate you enter is applied gross. For a taxable account, use an after-tax return; for funds with expense ratios, reduce the rate or use the investment fee calculator alongside this projection.
How is return on investment defined here?
ROI is (future value ÷ total contributions) − 1, expressed as a percent. It is not an annualized IRR. Two plans with the same ROI can have very different time horizons.
Why does a longer horizon increase growth so sharply?
Compounding applies the return to a larger base each year, and each contribution has more time to earn interest. That is why raising the term often changes the result more than a small change in the monthly amount.