Average Share Price Calculator
Work out your average (cost base) price per share across multiple purchases at different prices and quantities.
Your results
Calculation breakdown
- Total cost
- (units1 × price1) + (units2 × price2)
- Average price
- total cost ÷ total units
Worked example
You bought 100 shares at $20.00 and later another 100 at $30.00. Your combined holding is 200 shares at a weighted average cost of $25.00 per share.
Assumptions
- Excludes brokerage; add it to each purchase price beforehand for a fully loaded average.
- Only models two purchase parcels; combine results to layer in additional purchases.
- Not a substitute for your official ATO cost base records.
How this calculator works
Enter up to two buy parcels of units and price to calculate the weighted average price per share across your combined holding. This is a common way to track your cost base when you have topped up a share position over time.
Frequently asked questions
Does this replace ATO cost base records?
No, keep your actual contract notes; this tool gives a quick estimate for decision-making, not an official tax record.
Can I add more than two purchases?
Run the calculator again treating your first combined result as the first parcel to layer in a third purchase.
Does it include brokerage?
No, enter the purchase price ex-brokerage, or add brokerage into each unit price beforehand for a fully loaded average.
Results are estimates only and are not financial, tax, legal or credit advice.