Dollar Cost Averaging Calculator

Dollar cost averaging (DCA) is an investment strategy where you invest a fixed amount of money at regular intervals, regardless of the current price. Instead of trying to time the market with a lump sum, you spread your purchases over time.

For example, investing $500 per month into an S&P 500 index fund means you automatically buy more shares when prices are low and fewer shares when prices are high. Over time, this tends to produce a lower average cost per share compared to buying at random times.

DCA is the strategy behind most 401(k) and retirement account contributions. Every paycheck, a fixed amount goes into your investments, building wealth consistently over decades.

Research from Vanguard and other institutions shows that lump sum investing outperforms DCA about two-thirds of the time, because markets trend upward and being fully invested sooner captures more of that growth.

However, DCA has important advantages:

• Behavioral benefit: It removes the anxiety of investing a large sum at the "wrong" time.
• Risk reduction: If the market drops shortly after you invest, DCA limits your exposure.
• Practical reality: Most people earn money over time and invest as they earn, making DCA the default approach.

For most investors, the lump sum vs. DCA debate is academic. What matters most is investing consistently over long periods, regardless of the specific approach.

DCA growth comes from two sources: your regular contributions and compound returns on the growing balance. The longer you invest, the more dominant compound returns become.

Consider investing $500 per month at 10% annual return:

• After 10 years: $102,422 portfolio ($60,000 contributed, $42,422 in gains)
• After 20 years: $382,846 portfolio ($120,000 contributed, $262,846 in gains)
• After 30 years: $1,130,244 portfolio ($180,000 contributed, $950,244 in gains)

Notice how gains eventually dwarf contributions. By year 30, compound growth has generated over 5x your total contributions. This is why starting early is the single most important factor in building wealth through investing.