How to use this calculator
- Enter purchase prices, comma-separated, matching share quantities, total purchase fees.
- Choose a display currency, then select Calculate. Results also update after a brief pause while you edit.
- Read the result with the assumptions below. Export details or save a second scenario to compare your choices.
Formula and method
Assumptions and limitations
All lots must represent the same security and currency. No sales, short positions, split adjustment or jurisdictional tax-lot accounting is performed.
Worked example
Two purchases of 100 shares at 10 and 100 at 20, plus total fees of 10, cost 3,010 for 200 shares: average 15.05.
What the result means
Find a weighted share acquisition cost including entered transaction fees.
Common questions
How is the calculation performed?
Average acquisition cost per share = (sum of price × quantity + total fees) / total shares.
What does the model leave out?
All lots must represent the same security and currency. No sales, short positions, split adjustment or jurisdictional tax-lot accounting is performed.
Methodology and transparency
Calculation specification reviewed on 2026-10-14. Mathematical implementation is tested against independent reference fixtures. This does not imply review by a licensed financial professional. Read the testing and precision policy.