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Stock Average Calculator

Bought the same stock at different prices? Find your average price per share, compare another purchase and see the price you need to break even after commission.

Choose a currency for display and enter all prices in that same currency. No exchange-rate conversion is performed. Quantities are whole shares.

Your stock purchases

Enter purchase prices and shares

#	Buy price per share	Shares	Purchase value

Example transactions are shown initially.

Commission is applied separately to purchases and a hypothetical sale. Actual sales, dividends, taxes and corporate actions are outside the scope of this calculation.

Position summary

EXAMPLE

Average price per share

Share-weighted average · Before fees

The break-even price covers purchase costs and the hypothetical selling commission.

Average down calculator: what if I buy more?

Based on the current position

New buy price per share

Additional shares

Scenario	Extra shares	Additional investment¹	New average price	Break-even price	Total shares

¹ Includes purchase commission. Scenarios are independent and do not change your purchase list. A lower average cost does not necessarily mean a smaller total loss or lower risk.

How is average cost calculated?

Each purchase price is weighted by the number of shares bought. Larger purchases have a greater effect on the average.

Average = Σ (purchase price × shares) / total shares

Break-even = total purchase cost including commission / [total shares × (1 − selling commission rate)]. This tool treats 1 lot as 1 share.

Purchase amount breakdown

Before commission

Scope of the calculation

You enter all prices and quantities; no live stock quotes are provided. Share quantities must be positive whole numbers and prices must be positive. Enter commission as a percentage from 0 to 10.

Purchase cost = Σ (price × shares) × (1 + commission / 100)Estimated net sale = scenario price × total shares × (1 − commission / 100)Net profit / loss = estimated net sale − purchase cost

This calculator models a purchase position. It does not process partial sales, dividends, rights issues, bonus issues, taxes or other charges. The scenario market price is chosen by you. Saved records remain in your browser; loading the example does not delete saved data.

How to use the stock average calculator

Enter the price per share and number of shares for each purchase. Add your broker’s percentage commission and a current or hypothetical share price. The calculator shows your weighted average, total amount invested, break-even price and estimated profit or loss after selling commission.

What does averaging down mean?

Averaging down means buying more shares below your existing average price. Use the scenario section to compare your current position with one, two or three additional purchases of your chosen size. Buying above your average raises it instead. Each scenario starts from the same original position.

Why is my break-even price higher than my average stock price?

The average price is calculated before commission. Break-even also covers purchase commission and the assumed commission on a future sale. With zero commission, these prices match.

Is a lower average price always better?

No. Buying more increases the money committed to the position. A lower average does not guarantee a smaller loss, a recovery or lower risk.

Is this a tax cost basis calculator?

No. It models the weighted average purchase price of one stock. It does not calculate tax lots, capital gains tax, FIFO, wash-sale adjustments, dividends, stock splits or partial sales. It provides calculations, not investment advice.