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Investment Growth Calculator: What Will It Be Worth?
Watch the part you didn't contribute take over.
This is the calculation that makes compounding click. Put in what you're starting with, what you add each month and how long you'll leave it — and you'll see the projected total, how much of it came out of your pocket, and how much appeared on its own.
The last number is the interesting one. Over short periods, almost everything in the total is money you contributed. Push the years out and the balance flips: growth becomes the majority of the balance. That crossover is the whole argument for starting early, and it's much more convincing as a number than as advice.
Good to know
What return rate should I use?
Lower is the safer assumption. A cautious figure keeps the projection honest, and it's worth running the calculation twice — once optimistic, once pessimistic — to see how wide the range really is.
Does this account for inflation?
No. The result is in today's currency units, not today's purchasing power. If you want a rough real-terms view, subtract expected inflation from the return rate before calculating.
Why does the growth portion accelerate so late?
Because each year's return is calculated on a larger base than the year before. Early on the base is small, so growth is small; the curve only becomes dramatic once the accumulated returns are themselves large enough to generate meaningful returns.
Is a monthly contribution better than a bigger starting amount?
Mathematically, money invested earlier has longer to compound, so a large start is powerful. In practice, most people don't have a lump sum — and a consistent monthly habit sustained for decades usually beats waiting to accumulate one.