Investment Balance with Monthly Contributions
Project a portfolio with regular contributions. Unlike ROI measured from realised proceeds, this worksheet applies your assumed future return at a constant rate.
- Runs in your browser
- Nothing is uploaded
- No signup; device limits apply
Numbers stay on your device. Nothing is sent to a server.
How to use this tool
Enter USD starting principal, end-of-month investment, annual return and years. Starting at zero works when monthly contributions are positive, but actual loss paths and varying returns are not represented.
Results and examples
Separate contributions from growth and do not interpret balance/contributions as an annualised return. Monthly compounding does not reconstruct a portfolio’s observed year-by-year performance.
Worked example
USD 1,000 plus USD 100 monthly for one year at 0% ends at USD 2,200 with zero investment growth.
Limitations
- Taxes, fees, inflation and purchase-date prices are excluded.
- The displayed growth is not a guaranteed investment gain.
Fields
| Field | Guidance and constraints |
|---|---|
| Starting amount | Accepted range: 0–100000000 · Input step: 100 |
| Monthly contribution | Accepted range: 0–1000000 · Input step: 10 |
| Annual return | Accepted range: 0–40 · Input step: 0.1 |
| Years invested | Accepted range: 1–60 · Input step: 1 |
Data handling
Processing stays in the current browser tab; the site does not upload tool input for the calculation itself.
Sources
Frequently asked questions
Is the contribution multiple CAGR?
No. It does not annualise timed cash flows.
Can starting principal be zero?
Yes, if monthly contributions are positive.
Related tools
You do not need to start over. Continue with the tool that fits your next step.
