When to use this calculator
Calculate a quantity-weighted average entry price across two purchases. Excludes fees and requires a positive total share quantity.
Explore the investment return calculators for other questions in this topic. For a related calculation, use the Bond Coupon Payment Calculator: Find the periodic coupon amount from bond face value and annual coupon rate.
PUTTING IT INTO PRACTICE
Average Cost Per Share: a worked example
The values below are an illustrative example, not a recommendation. Replace them with measurements or assumptions that match your question.
| Input | Example value |
|---|---|
| First purchase shares | 10 |
| First price per share | 20 |
| Second purchase shares | 30 |
| Second price per share | 10 |
| Result | 12.5 per share |
- Check the input labels and enter the example values above.
- Apply the relationship: Average unit cost = (shares₁×price₁ + shares₂×price₂)/(shares₁+shares₂).
- The result is 12.5 per share, rounded for display.
How to interpret your result
Excludes fees and requires a positive total share quantity.
Return measures must cover the same time period before comparison. CAGR annualises two endpoint values but does not model interim cash flows. Current income yield differs from total return or yield to maturity.
Frequently asked questions
Can CAGR handle money added during the period?
The simple endpoint CAGR model does not account for intermediate deposits and withdrawals. Those require cash-flow-aware methods.
When is the average cost per share calculator useful?
Calculate a quantity-weighted average entry price across two purchases. Excludes fees and requires a positive total share quantity.
How do I use the average cost per share calculator?
Enter first purchase shares, first price per share, second purchase shares, second price per share. The result updates automatically. Use the units shown beside each input; the example values illustrate the method.
Which formula does this calculator use?
Average unit cost = (shares₁×price₁ + shares₂×price₂)/(shares₁+shares₂).
What should I check before using the result?
Excludes fees and requires a positive total share quantity.
How are results rounded?
Scalar numbers display up to six decimal places, with scientific notation for very large or small values. Text, fraction, date and schedule outputs use the format described on the tool. Intermediate calculations use JavaScript floating-point arithmetic. Keep sensible precision for your measurements.
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