ETF Compound Growth Calculator
See how regular investing compounds over time. Enter a starting balance, a monthly contribution and an expected annual return to project what your ETF portfolio could be worth — and how much of it is pure growth.
Assumes contributions are added at the end of each month and the return compounds monthly. A real ETF return varies year to year — use the Monte Carlo simulator to see the range.
Worked example
Start with $10,000, add $500 a month, and assume a 7% annual return (a common long-run assumption for a broad equity ETF) for 20 years. You would contribute $130,000 in total, but compounding turns it into roughly $300,000 — meaning about $171,000 of the balance is investment growth, not your own money. That gap is the entire case for starting early.
The power of compounding
Compounding means your returns earn returns. Early contributions have the most time to grow, so the balance curve bends upward — the second decade adds far more than the first, even with identical contributions. This calculator compounds monthly and adds your contribution at the end of each month, which mirrors how most people invest.
Be realistic about returns and fees
A single fixed return hides real-world volatility and costs. Use a conservative figure (many investors model 5–7% after inflation), remember that fees compound against you just as returns compound for you, and stress-test the plan with the Monte Carlo simulator to see the range of outcomes rather than a single smooth line.
Frequently asked questions
- What return should I assume for an ETF?
- Broad equity index ETFs have historically returned roughly 7–10% per year before inflation over long periods, but any single decade can be very different. Use a conservative number and revisit it.
- Does this account for inflation?
- Not directly. To see today's purchasing power, enter a real (after-inflation) return — for example 5% instead of 8%.
- How is the future value calculated?
- It compounds your starting balance monthly and adds your contribution at the end of each month for the full horizon, then reports the ending value, total contributed and the growth portion.
- Can I model dividends being reinvested?
- Yes — use a total-return figure (price growth plus reinvested dividends) as your expected annual return.
Project your actual ETF portfolio
TrimmTrack's forecast tool models contributions, fees, rebalancing and Monte Carlo volatility across your real ETF mix.