Dollar-Cost Averaging Calculator
Project what investing a fixed amount at regular intervals could grow into, with total invested, gains, and a growth chart.
Frequently Asked Questions
What is dollar-cost averaging?
Investing a fixed amount at regular intervals regardless of price. It averages your purchase cost over time and removes the pressure of timing the market.
How is the final value calculated?
Using the future value of a regular-contribution annuity, compounding each contribution at your expected periodic return until the end of the period.
Is the return guaranteed?
No. Real returns vary; the expected return you enter is an assumption, so treat the result as an estimate.
Understanding the Dollar-Cost Averaging Calculator
Dollar-cost averaging (DCA) means investing a fixed dollar amount at regular intervals, regardless of price. This calculator estimates how a recurring contribution into a stock, ETF, or fund could have grown, showing total invested, shares accumulated, average cost per share, and ending value. It is built for long-term investors, retirement savers, and anyone running automatic monthly contributions who wants to see the math behind their plan. Results are educational estimates based on the return assumptions you enter, not predictions or investment advice.
How it works
You enter a periodic contribution (say $500), a frequency (weekly, monthly), a time horizon, and either a fixed expected return or a sequence of prices. Each period the calculator buys contribution ÷ price shares, accumulates them, and applies growth. Buying the same dollar amount means you automatically purchase more shares when prices are low and fewer when high, lowering your average cost per share versus a lump-sum bought at the average price. Read three outputs together: total invested (your principal), ending value, and average cost per share. The gap between total invested and ending value is your estimated gain or loss.
Worked example
You invest $500 monthly for 12 months. Over the year the share price is $50, $40, $45, then recovers to $55 by month 12. At $50 you buy 10 shares; at $40 you buy 12.5; at $45 you buy 11.1, and so on. Suppose you accumulate 124 shares for $6,000 invested — an average cost of about $48.39 per share, below the simple average price. At a final $55 price, ending value is 124 × $55 = $6,820, an estimated gain of $820.
Tips & common mistakes
- DCA reduces timing risk and emotion, but research shows lump-sum investing often wins on average when markets trend up — DCA's edge is behavioral and risk-smoothing, not guaranteed higher returns.
- Average cost per share is not the same as average price; buying fixed dollars weights cheaper periods more heavily.
- Set return assumptions conservatively. Past returns (e.g., long-run ~7% real for broad US equities) do not guarantee future results.
- Account for fund fees, trading commissions, and taxes — they reduce the ending value this estimate shows.
- Automating contributions enforces discipline, but rebalance and review your plan periodically rather than ignoring it.
Sources & methodology
- • U.S. SEC Investor.gov — Dollar Cost Averaging (https://www.investor.gov/introduction-investing/investing-basics/glossary/dollar-cost-averaging)
- • FINRA — Investing concepts and risk (https://www.finra.org/investors/investing)
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Reviewed by the TopOpenTools editorial team · Last updated June 2026. These tools provide general estimates for educational purposes only and are not financial, tax, insurance, investment, or medical advice. Verify important decisions with a qualified professional.