Investment growth with regular contributions
An investment projection separates the money you contribute from the growth you assume. This calculator combines an initial investment with a fixed monthly contribution over your chosen number of years. It displays future value, total contributed and compound gains in the selected country's currency. Use it to compare saving habits and time horizons, not to predict an actual stock price or future portfolio value. A positive constant return is an illustrative assumption; real markets can decline and investment values are not guaranteed.
The timing behind the formula
This page uses FV = P × (1 + a)^t + C × ((1 + m)^(12t) − 1) / m × (1 + m), where P is initial investment, C is the monthly contribution, a is the annual decimal rate, m = a / 12 and t is years. The initial balance compounds annually; monthly deposits use monthly compounding and are assumed to arrive at the beginning of each month.
These are different rate conventions for the two parts of the projection. The result can differ from a calculator that compounds the entire balance monthly or assumes end-of-month contributions. At zero return, future value is simply P + C × 12t. Compare tools only after checking their timing and compounding assumptions.
Interpret contributions and gains
Total contributed is your starting balance plus every scheduled monthly deposit. Compound gains are projected future value minus that total. Gains are not a guaranteed payout and do not include taxes, fees or inflation. There is no automatic inflation adjustment on this page. To estimate future purchasing power, divide the result by a separately assumed inflation factor.
Regular investing spreads purchase dates over time, but does not eliminate loss or ensure a lower average price. Choose contributions that fit your budget and compare several return assumptions. A longer horizon creates more opportunities for compounding but also more uncertainty. Check product charges and investment risk before turning a calculator scenario into an actual investment decision.
Worked examples
USD 10,000 plus USD 200 monthly
At an illustrative 6% annual return for ten years, the initial balance grows to USD 17,908.48 and the beginning-of-month contributions grow to USD 32,939.75. Future value is USD 50,848.23, contributions are USD 34,000 and projected gains are USD 16,848.23.
No-return baseline
With the same initial USD 10,000 and USD 200 monthly for ten years at 0%, the total is USD 34,000 with no compound gains. This baseline isolates what your own deposits achieve without assuming market growth.
Frequently asked questions
Are deposits made at the start or end of the month?
The monthly contribution formula assumes beginning-of-month deposits. End-of-month contributions would have one fewer monthly growth period.
Does this automatically adjust for inflation?
No. Results are nominal currency amounts. Inflation, fees and taxes require separate assumptions.
Does regular investing prevent losses?
No. Spreading purchases over time does not remove investment risk or guarantee a profit.
What happens when the return is zero?
The future value equals the initial amount plus every scheduled contribution, with no compound gains.