Dollar-Cost Averaging (DCA) Calculator
See how consistent monthly investing builds wealth over time — and compare DCA to investing a lump sum upfront.
What if you invested the same total amount as a single lump sum at the very start?
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What Is Dollar-Cost Averaging?
Dollar-cost averaging (DCA) means investing a fixed amount on a regular schedule — regardless of market conditions. When prices are high, your fixed amount buys fewer shares. When prices are low, it buys more. Over time, this averages out your cost per share and removes the temptation to time the market.
Why DCA Works — Removing Timing Risk
No one consistently knows when markets will peak or trough. Studies show even professional fund managers rarely beat the market over long periods. DCA sidesteps this problem entirely: you invest the same amount every month, automatically buying more when things are cheap and less when they're expensive.
DCA vs Lump Sum — Which Wins?
Mathematically, in a consistently rising market, a lump sum invested at the start will outperform DCA — because more money is exposed to growth for longer. Research by Vanguard found lump sum beats DCA about two-thirds of the time over 12-month windows. However, DCA wins in volatile or declining-then-recovering markets, and critically, it wins psychologically — most people don't have a large lump sum available and wouldn't have the nerve to invest it all at once.
Best Practices for Index Fund DCA
Set up automatic contributions to a low-cost index fund (like an S&P 500 ETF), ideally in a tax-advantaged account (401k, IRA, ISA). Automate the transfer so it's effortless. Reinvest all dividends. Don't check the balance obsessively — the power of DCA is in consistency over time, not in short-term performance.