Dollar Cost Averaging Calculator
Compare investing available cash at once with equal monthly purchases over a selected deployment period
DCA vs. lump sum investing
When cash is already available, lump sum investing puts it to work sooner, while dollar cost averaging spreads equal purchases across the selected period. Neither approach is universally better. This calculator provides an illustration based on your entered return and volatility assumptions, not a prediction of future results.
Neither approach is universally better. This illustration uses your entered assumptions and is not a prediction of future results.
Strategy Comparison
Portfolio Value Over Time
Methodology, sources, and privacy
This calculator compares investing cash that is already available with a monthly deployment schedule on one deterministic price path. It is a reproducible scenario illustration, not a forecast or a recommendation.
- Calculation convention
- The model applies the entered annual return and volatility to a deterministic sine-wave price path, then compares equal monthly purchases with investing the full balance at the start.
- Timing convention
- Lump sum is invested at the start. DCA contributions are invested at the start of each monthly period. Uninvested cash earns 0% in this model.
- Model version
- dca-deterministic-v1
- Last reviewed
- 2026-08-02
Defaults
- Deployment period: 2 years and 0 months
- Purchase cadence: Monthly
- Model type: Deterministic scenario illustration
- Uninvested cash: No return modeled while waiting
Not modeled
- Historical prices, probabilities, Monte Carlo paths, and predictive claims
- Taxes, fees, dividends, fund-specific behavior, and account rules
- Paycheck contributions or a recommendation about which strategy to choose
Sources
- FINRA: Dollar-cost averaging Accessed 2026-08-02
- Investor.gov: Dollar cost averaging Accessed 2026-08-02
Privacy: Inputs stay in your browser for this calculator. Firebasis does not need an account or personal identifying information to run it.
Financial-content boundary: This is general U.S.-oriented financial education, not individualized financial, tax, or investment advice.
Frequently Asked Questions
What is dollar cost averaging (DCA)?
Dollar cost averaging is an investment strategy where you invest a fixed amount of money at regular intervals, regardless of market conditions. It spreads your purchase timing over time, which may reduce the risk of committing all of your money immediately, but it does not guarantee a lower average cost or a higher return.
Is lump sum investing better than DCA?
Neither strategy is always better. Investing a lump sum puts the money in the market sooner, while DCA spreads purchases across the selected period. The better fit depends on your cash availability, risk tolerance, and comfort with market timing. Use this calculator as an illustration under the assumptions you enter, not as a prediction.
When should I use dollar cost averaging?
DCA may fit when an investment balance is already available and you prefer a repeatable monthly schedule rather than choosing one entry date. Investing future paycheck contributions is a separate cash-flow decision because that money is not available before it arrives.
What is the main advantage of DCA?
The main advantage of DCA is a repeatable investing process. You invest equal amounts on schedule, buying more shares when prices are lower and fewer when prices are higher. That process can make investing easier to follow, but it cannot remove market losses or predict future prices.
What does this dollar cost averaging simulator assume?
The simulator invests equal amounts at the start of each month for the selected deployment period, compares that with investing the full available balance at the start, and applies your entered assumptions to a deterministic sine-wave price path. Uninvested cash earns 0% while waiting. It is not historical, probabilistic, Monte Carlo, predictive, or a forecast of future performance.
Read the full explanation
When cash is already available, lump sum investing puts it to work sooner, while dollar cost averaging spreads equal monthly purchases across the selected deployment period. Future paycheck contributions are a separate cash-flow decision. Neither approach is universally better, and this calculator provides a deterministic scenario illustration, not a forecast.
Understanding Dollar Cost Averaging
Lump sum investing puts available cash to work sooner, while dollar cost averaging spreads purchases across time. Neither approach is universally better.
DCA vs. Lump Sum: What the Comparison Shows
When cash is already available, lump sum investing gives it more time in the market and may produce a higher ending value under a rising price path. DCA can reduce the pressure of choosing one entry date by spreading purchases across the selected period.
- Lump sum invests the full amount on day one.
- DCA invests equal amounts each month.
- DCA may make it easier to follow a consistent plan.
- A higher modeled value does not establish which strategy is right for you.
Scenario Assumptions and Limits
This calculator uses your expected annual return and volatility to create a deterministic sine-wave price path, then applies the two contribution schedules to that same path. The result is an illustration under entered assumptions, not a forecast of market behavior or future performance.
- The model does not simulate a range of possible market paths.
- It does not account for taxes, fees, dividends, or fund-specific behavior.
- Actual returns can differ materially from the entered assumptions.
When DCA May Fit
DCA may be useful when an available balance is ready to deploy and you prefer a repeatable monthly schedule. Future paycheck investing is a separate contribution-timing decision.
- Automate your investments to remove emotion.
- Review the plan against your cash flow and risk tolerance.
- Keep the difference between an illustration and a forecast in mind.