Portfolio Growth Calculator
See how your investments grow over time with monthly contributions and compound returns.
Who This Is For
Anyone who wants to see the long-term impact of consistent investing. Whether you're just starting out or want to project your current strategy forward, this calculator shows the power of compound growth.
Example Scenario
You start with $5,000 and invest $500/month for 20 years at 7% annual returns.
Result: Your portfolio grows to about $270,000— you contributed $125,000 and compound growth added another $145,000.
How It Works
This calculator models monthly investing with compound growth:
- Start with your initial investment
- Add your monthly contribution each month
- Apply the expected annual return (divided into monthly)
- Repeat for the full investment period
The year-by-year table shows how contributions and growth accumulate. Notice how growth accelerates in later years—that's compounding at work.
Assumptions and Formula
Assumptions used in this model:
- Fixed annual return assumption translated into monthly compounding.
- Fixed monthly contributions for the full horizon.
- No taxes, fees, or contribution caps are applied.
Compound growth formula: future value = principal growth + annuity growth, simulated month-by-month for more realistic contribution timing.
How to Interpret Your Results
| Signal | What It Means | Action |
|---|---|---|
| Growth overtakes contributions late in timeline | Compounding is doing most of the work | Protect consistency; avoid stopping contributions |
| 5-year result looks modest | Short horizon limits compounding effect | Extend horizon before increasing risk |
| Small rate changes swing final value heavily | Return sensitivity is high | Use pessimistic/base/optimistic planning bands |
Educational tool, not financial advice. Past performance does not guarantee future results. Actual investment returns vary. Tax implications not included.
Frequently Asked Questions
Deep Dive Guide
Read the Financial Priority Ladder guide
Place portfolio growth in the right sequence with cash reserves and debt goals.