Dollar-Cost Averaging Calculator

Reviewed by the CalculatorHub team, edited by James Graham. Standard DCA average cost formula. Last verified 15 June 2026.

Dollar-cost averaging (DCA) is a disciplined investment strategy that involves buying a fixed dollar amount of an investment at regular intervals, regardless of the share price. This approach automatically purchases more shares when prices are low and fewer when prices are high, resulting in a lower average cost per share than the arithmetic average price paid. This calculator lets you enter up to five purchase rounds with different dollar amounts and prices to see your total invested, total shares acquired, and the resulting average cost per share. You can also enter a current market price to see your current gain or loss.

Purchase 1: amount ($)

Purchase 1: price per share ($)

Purchase 2: amount ($)

Purchase 2: price per share ($)

Purchase 3: amount ($) optional

Purchase 3: price per share ($) optional

Purchase 4: amount ($) optional

Purchase 4: price per share ($) optional

Current market price ($)

Total invested ($)

0.00

Total shares

0.00

Average cost per share ($)

0.00

Current value ($)

0.00

Unrealized gain / loss ($)

0.00

DCA average cost formula

Shares purchased = amount / price per share
Total shares = sum of all shares purchased
Total invested = sum of all amounts
Average cost = total invested / total shares

The DCA average cost is always less than or equal to the arithmetic average of the prices paid, because more shares are purchased at lower prices. This is the harmonic mean effect.

Benefits and limitations of DCA

DCA removes the emotional burden of timing the market and enforces investment discipline.
401(k) contributions from each paycheck are a common form of automatic DCA.
DCA tends to lag lump-sum investing in consistently rising markets; it excels in volatile or declining markets.
Transaction costs per purchase can add up; commission-free platforms make DCA more practical today.
DCA is especially powerful for long-term wealth building in index funds because it captures the full range of prices over market cycles.

Frequently asked questions

What is dollar-cost averaging?

Dollar-cost averaging (DCA) is an investment strategy where you invest a fixed dollar amount at regular intervals regardless of price. When prices are low, your fixed amount buys more shares; when prices are high, it buys fewer. Over time, this averages out the purchase price.

How is average cost calculated with DCA?

Average cost per share = total amount invested / total shares purchased. If you invested $1,000 twice, once at $50/share (20 shares) and once at $40/share (25 shares), your total is $2,000 for 45 shares, giving an average cost of $44.44 per share.

Does DCA reduce risk?

DCA reduces timing risk by spreading purchases over time, which prevents investing a lump sum at a market peak. However, in a steadily rising market, lump-sum investing tends to outperform DCA on average because more money is invested sooner. DCA reduces emotional decision-making.

Is DCA better than lump-sum investing?

Research by Vanguard and others has found that lump-sum investing outperforms DCA about two-thirds of the time in rising markets because more capital is deployed earlier. However, DCA is a sound strategy for investors who receive income periodically (e.g., 401(k) contributions from each paycheck).

Does the SEC regulate DCA plans?

DCA is a personal investment strategy, not a regulated plan. However, automatic investment plans offered by brokers and mutual fund companies are regulated by the SEC. Dividend reinvestment plans (DRIPs) are a specific form of automatic investment subject to SEC disclosure requirements.

Official sources

SEC: Dollar-Cost Averaging.
IRS: Topic 703 - Basis of Assets.

Reviewed by the CalculatorHub team, edited by James Graham, 15 June 2026. See our methodology.