Dollar-Cost Averaging (DCA) Calculator
See why investing a little each month beats trying to time the market.
Compare DCA vs lump sum with CAGR analysis and inflation adjustment.
What is dollar-cost averaging?
Dollar-cost averaging means investing a fixed amount on a regular schedule regardless of what the market is doing. When prices are down you automatically buy more shares, when they're up you buy fewer. Over time this smooths out your average cost per share without requiring you to predict anything.
The stronger case for it is behavioral: a consistent strategy you stick to through a down market will outperform an optimal strategy you abandon. Set your monthly amount and time horizon to see what regular, automated investing actually compounds to.
The honest case for DCA is not that it maximizes returns. It doesn't. In rising markets, lump-sum investing outperforms roughly two-thirds of the time, because capital deployed earlier has more time to compound. The case for DCA is variance reduction and the management of behavioral risk. An investor who commits a fixed amount monthly is insulated from the catastrophic timing error of deploying a lump sum immediately before a significant correction.
The contribution step-up formula is worth paying attention to. Increasing contributions by even 2-3% annually, roughly in line with wage growth, has a compounding effect on the final balance that's disproportionate to the extra capital deployed. The additional money goes in earlier in each subsequent year's cycle, earning more time than a flat-contribution model assumes.
One caveat the calculator's constant-rate assumption cannot capture: DCA's real-world edge is most pronounced in volatile markets, precisely because the fixed-amount mechanic naturally buys more shares at depressed prices. In a steady upward-trending market, lump sum wins. In a volatile one, DCA's average cost per share comes in below the period's average price. Whether the next decade looks more like the former or the latter is a question the calculator can't answer, but inflation-adjusting the final figure before drawing conclusions is non-negotiable.
Dollar-cost averaging calculator: common questions
How does this dollar-cost averaging calculator work?
Enter a fixed monthly amount, a time horizon, and an expected annual return. The calculator compounds each monthly contribution forward to the end of your horizon, so you see the final balance, total contributions, growth, CAGR, and the inflation-adjusted value. Switch to Pro mode to add a lump sum for a side-by-side comparison.
Can I use it as an S&P 500 DCA calculator?
Yes. Set the expected annual return to match the index you're modeling — the S&P 500 has averaged roughly 10% a year over the long run, though 6–7% is a more conservative planning figure after inflation. The math is the same whether you're dollar-cost averaging into an S&P 500 index fund, a total-market fund, or any other holding with a steady assumed return.
Is dollar-cost averaging better than investing a lump sum?
Not for raw returns. In rising markets, deploying a lump sum wins roughly two-thirds of the time because the money has longer to compound. DCA's advantage is variance reduction and behavioral discipline: a fixed monthly amount protects you from the worst-case timing of investing everything right before a correction, and it's a strategy most people can actually stick to. Turn on Pro mode to compare both side by side.
Can I use this DCA calculator for individual stocks?
You can, with a caveat. The calculator assumes one constant rate of return, which is a reasonable simplification for a diversified index fund but a poor fit for a single stock, where real returns are far more volatile and uncertain. Treat any single-stock projection as illustrative rather than predictive.
Does it use historical or projected returns?
Projected. You choose the expected annual return and the tool grows your contributions at that constant rate — it does not replay historical market data. To stress-test a plan, run it a few times with different return assumptions (for example 5%, 7%, and 10%) and always check the inflation-adjusted figure before drawing conclusions.