Dollar-Cost Averaging Calculator
Enter a fixed contribution amount and a sequence of market prices to calculate your average cost basis, total units purchased, and performance at today’s price.
What is cost averaging?
Cost averaging (often called dollar-cost averaging, or DCA) is the strategy of investing the same amount of money at regular intervals instead of investing one big lump sum all at once. When prices are high, your fixed contribution buys fewer units. When prices are low, the same contribution buys more units. Over time, this creates an average purchase cost that can reduce timing risk.
How this calculator works
This calculator assumes:
- You invest the same dollar amount each period.
- Each period has one market price.
- Your contribution is fully invested each period.
Using those inputs, it computes total invested capital, total units accumulated, and your average cost per unit. It also estimates current portfolio value and compares your DCA result with a lump-sum purchase made at the first price.
Core formulas
- Units bought each period = Contribution ÷ Price
- Total units = Sum of all units bought
- Average cost per unit = Total invested ÷ Total units
- Portfolio value = Total units × Current price
Why investors use this strategy
- Consistency: Encourages regular investing habits.
- Less emotional timing: Reduces pressure to “buy at the perfect moment.”
- Volatility benefit: In choppy markets, buying more at lower prices can improve cost basis.
- Simple automation: Works well with scheduled transfers and retirement plans.
Important limitations
Cost averaging is not guaranteed to outperform lump-sum investing. In a steadily rising market, investing earlier with a lump sum can lead to better results because more money is in the market for longer. DCA is mainly a risk-management and behavior strategy, not a magic return booster.
What this calculator does not model
- Trading fees, spreads, and taxes
- Dividends or distributions
- Irregular contribution schedules
- Inflation and opportunity cost
Practical tips for better results
- Set a contribution amount that you can sustain through market cycles.
- Automate contributions to remove decision fatigue.
- Review your plan periodically, but avoid constant tinkering.
- Diversify instead of concentrating only in one asset.
Quick FAQ
Is cost averaging good for beginners?
Yes. It’s straightforward, disciplined, and helps avoid all-in timing mistakes.
Can I use this for stocks, ETFs, or crypto?
Absolutely. As long as you can provide periodic prices and a fixed contribution amount, the math is the same.
Is this financial advice?
No. This is an educational calculator. Always consider your risk tolerance, goals, and time horizon before investing.