Estimate the future value of a lump-sum investment plus regular monthly contributions, based on your expected annual return and compounding frequency.
| Year | Contributions | Interest | Balance |
|---|
What Is an Investment Return Calculator?
An investment return calculator projects how much an investment could grow over time by combining a lump-sum starting amount, regular monthly contributions, an expected annual rate of return, and a chosen compounding frequency. This free browser-based calculator runs entirely on your device — no data is sent to a server.
How the Calculation Works
The calculator converts your annual return and compounding frequency into an effective monthly rate, applies it to your balance each month, and adds your monthly contribution at the end of each period. The standard compound interest formula for a lump sum is:
FV = P × (1 + r/n)^(n×t)
Where P is the initial investment, r is the annual interest rate,
n is the number of compounding periods per year, and t is time in years.
Regular monthly contributions are added on top of this using the future value of an annuity formula.
For the underlying math, see Investor.gov’s official compound interest explainer. For a dedicated compounding-only
calculation, SmartWebHub also has a Compound
Interest Calculator.
Compounding Frequency Comparison
| Frequency | Periods per Year | Effect |
|---|---|---|
| Annually | 1 | Interest applied once a year |
| Semi-Annually | 2 | Interest applied twice a year |
| Quarterly | 4 | Interest applied every 3 months |
| Monthly | 12 | Interest applied every month — most common for savings/investment accounts |
| Daily | 365 | Interest applied every day — slightly higher effective return than monthly |
Why Compounding Frequency Matters
More frequent compounding produces a slightly higher effective annual return for the same nominal rate, because interest starts earning interest sooner. The difference is usually small for typical savings rates but becomes more noticeable over long time horizons or with higher rates.
Common Use Cases
This calculator is useful for estimating retirement savings growth, comparing different contribution amounts, seeing the long-term effect of starting to invest earlier, and understanding how compounding frequency affects returns. It provides estimates only — actual investment returns vary and are not guaranteed. If you also need to factor in taxes on investment income, try the Salary Tax Calculator, or convert returns across currencies with the Currency Converter.
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Frequently Asked Questions
Investment return is calculated by applying compound interest to your initial investment and any regular contributions, using your expected annual rate and compounding frequency.
This varies by investment type and risk level; many long-term stock market projections cite the SEC’s investor education resources as a starting point, but actual future returns are not guaranteed.
For most typical rates, the difference between monthly and daily compounding is small, but it compounds further over long periods and higher rates.
It provides a mathematical projection based on a fixed rate of return. Real investments fluctuate, so actual results will differ from a constant-rate projection.
No. All calculations run locally in your browser using JavaScript; nothing is transmitted or saved.
This tool is for educational and estimation purposes only and does not constitute financial advice.