Investment Calculator — Growth with Regular Contributions
See how your investment grows over time. Enter an initial lump sum, a regular contribution, an expected annual return and an investment horizon to get the final portfolio value, total contributions, and the power of compounding shown year by year.
%
years
Compounding frequency
Initial investment + contributions + all interest/returns compounded
- 1
Rate per period
7 % ÷ 12 = 0.005833 - 2
Total periods
20 × 12 = 240 - 3
Growth factor (1+r)ⁿ
(1 + 0.005833)ⁿ = 4.0387 - 4
Lump-sum future value
10,000 × 4.0387 = 40,387.39 - 5
Contributions future value
200 × (4.0387 − 1) ÷ 0.005833 = 104,185.33 - 6
Final portfolio value
40,387.39 + 104,185.33 = 144,572.72
How does this calculator work?
FV = PV × (1 + r)^n + PMT × [(1 + r)^n − 1] / r. Enter an initial sum, regular contribution, annual return, and years to see your final portfolio value. The model compounds at the chosen frequency (monthly/quarterly/annually) and assumes a fixed return rate — no taxes, fees, or inflation included.
Formula
How this is calculated
The calculator combines two standard time-value-of-money formulas. The lump-sum component grows to PV × (1 + r)^n, where r is the rate per compounding period and n is the total number of periods. The regular contributions are treated as an ordinary annuity — each contribution is made at the end of its period and then compounds for the remaining periods. The annuity formula PMT × [(1 + r)^n − 1] / r adds up the future values of all contributions efficiently without iterating over each one.
Choosing a compounding frequency of monthly (n = 12 × years) and making contributions at that same frequency is a realistic model for a regular savings or investment plan. Quarterly matches plans with quarterly dividends reinvested. Annual is the simplest approximation. For the same nominal rate, more frequent compounding yields a slightly higher balance.
All figures are nominal — they ignore inflation and taxes. The expected annual return is your input and should be a long-run estimate appropriate for the asset class (for example, global equity index funds have historically averaged roughly 7–10% per year over decades in nominal terms, though past performance is not guaranteed). Real purchasing power of the final balance will be lower after inflation, and taxes on gains may apply depending on your jurisdiction.
Frequently asked questions
It depends on the asset class. Broad equity index funds have historically returned roughly 7–10% nominally before fees and taxes. Bonds and cash equivalents typically return less. Use a conservative figure — 5–7% nominal is a common planning assumption — and check how sensitive the outcome is by varying the rate.
Compounding means each year's returns earn returns themselves. Early contributions have the most time to compound, so the "interest on interest" effect snowballs. This is why starting early matters far more than the size of individual contributions.
No — all figures are nominal. To estimate real purchasing power, subtract your expected annual inflation rate from the return rate before entering it (for example, 7% nominal − 2.5% inflation ≈ 4.5% real).
Also known as
TG we-Calculate Editorial Team. (2026). Investment Calculator — Growth with Regular Contributions [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/investment-calculator
TG we-Calculate Editorial Team. "Investment Calculator — Growth with Regular Contributions." TG we-Calculate. 2026. https://we-calculate.com/calculator/investment-calculator.
TG we-Calculate Editorial Team, "Investment Calculator — Growth with Regular Contributions," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/investment-calculator
@misc{wecalculate_investment_calculator, title = {Investment Calculator — Growth with Regular Contributions}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/investment-calculator}}, year = {2026}, note = {TG we-Calculate} }
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