Why does the comparison matter?

If you have a windfall ($30k bonus), the math says invest it all immediately. If you have a steady paycheck, you're already DCA'ing — that's fine.

What rate should I use?

For US stock indexes long-term, 7-10%. For balanced 60/40 portfolio, 5-7%. Avoid using recent short-term returns as a baseline.

Dollar-Cost Averaging Calculator

Outcome of investing a fixed amount monthly over time.

Result

DCA final value (after 60 months)

$36,983.35

Total invested via DCA$30,000.00
Gain from DCA$6,983.35
— Comparison: lump-sum —
$30,000.00 invested upfront grows to$44,695.37
Lump-sum gain$14,695.37
DCA wins bypositive = DCA produced more dollars-$7,712.02

How to use this calculator

Enter your planned monthly contribution.
Set the time horizon in months (60 = 5 years, 120 = 10 years).
Use 7-8% for long-term US equity returns.
In the lump-sum field, type what you'd alternatively invest upfront for an apples-to-apples comparison.

About this tool

Dollar-cost averaging (DCA) means investing a fixed dollar amount on a regular schedule regardless of price — you buy more shares when prices are low, fewer when they're high. This calculator shows what a fixed monthly investment grows to over time at an average return rate, plus a side-by-side comparison with investing the same total amount upfront (lump-sum). Honest answer: lump-sum mathematically beats DCA about 2/3 of the time in the historical US market. DCA wins as a behavioral tool — it's the strategy you can actually stick to when markets dip.

Frequently asked

Mathematically: usually no. Vanguard study: lump-sum beat DCA in ~67% of historical 10-year periods. Behaviorally: DCA wins because it's easier to do consistently.