DCA Calculator
Compare dollar-cost averaging (investing a fixed amount regularly) against a lump-sum investment.
Enter your values to calculate your result.
Formula
Each month, invest Total Amount ÷ Months at that month's share price; DCA Value = Total Shares × Ending Price
The share price is assumed to move in a straight line from your Starting Price to your Ending Price over the period — a simplification, since real prices fluctuate. Dollar-cost averaging buys more shares when the modeled price is lower and fewer when it's higher, which is compared against investing the entire amount at once (lump sum) at the Starting Price.
Example
Investing $12,000 over 12 months as the price rises steadily from $100 to $120 ends with a DCA value of about $13,134 — compared to about $14,400 if the full $12,000 had been invested as a lump sum at $100.
Frequently Asked Questions
Why would DCA ever be worse than a lump sum?
When the price rises steadily, a lump sum invested at the lower starting price captures the full gain on all your money immediately — DCA only gradually puts money in as the price rises, missing some of that growth. DCA's real benefit shows up when prices are volatile or falling, since it buys more shares cheaply along the way.
Is the straight-line price path realistic?
No — real markets fluctuate up and down, not in a straight line. This model is a simplified illustration of the DCA mechanism using just a start and end price, not a prediction of real returns.