Average cost calculator
What did I actually pay per share?
Enter the amount you invest each time and the prices you paid to get your true average cost per share, and to see why it usually sits below the simple average price.
- Written by
- Pro Investor Academy Research Team
- Content type
- Calculator
- Published
- 2026-09-13
- Last reviewed
- 2026-09-13
Purchases
6
Total invested
$3,000
Shares acquired
29.279
Average cost per share
$102.46
The simple average price was $103.50. Investing the same dollar amount each time buys more shares at lower prices, so average cost is at or below the average price in this scheme. It does not mean a profit: that depends on what the shares are worth later.
How to read the result
- Compare average cost with average price. The gap is the mechanical benefit of buying a fixed dollar amount rather than a fixed number of shares.
- Average cost is a record of what you paid. It is not a target, a break-even you must defend, or a reason to sell.
- Adding purchases at lower prices lowers average cost; it does not make a weak business a good one.
What this calculator cannot tell you
- Commissions, fractional-share rules and taxes are not modelled.
- Your broker's cost basis is the figure that matters for tax; this is an illustration.
- Arithmetic on the prices you enter, nothing more.
Terms used here
Sources and methodology
Standard future-value arithmetic. Every figure is hypothetical and depends entirely on the assumptions you enter.
- Investor.gov investor education — U.S. Securities and Exchange CommissionPrimary source
- Intelligent Accumulation methodology — Pro Investor AcademyPrimary source
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