ETF overlap tool
Pick two ETFs, see how much they actually share. Stop "diversifying" by buying Apple, Microsoft, and Nvidia three times.
Plug in a starting amount, a monthly contribution, and how long you can leave it alone. The math does the rest — and shows you, year by year, how much of your future balance is money you put in vs. money your money made.
| Year | Contributions | Interest | Balance |
|---|
Each period, your balance earns the periodic interest rate (annual ÷ periods), then your contribution gets added on top. Repeat that for every month for thirty years and the curve goes from "boring straight line" to "wait, what?" That bend is compounding.
The formula, if you're into that sort of thing: FV = P(1+r)^n + PMT · ((1+r)^n − 1) ÷ r
Heads up: this assumes a constant return, which real markets do not provide. It's a planning tool, not a prediction. Nothing here is investment advice.
Pick two ETFs, see how much they actually share. Stop "diversifying" by buying Apple, Microsoft, and Nvidia three times.
Because a 7% nominal return and a 7% real return are very different animals.
How much do you need to contribute to capture the full match? (Spoiler: probably more than you think.)