Stock Average Calculator (Average Cost)

Quick answer

The stock average calculator works out the average price you paid per share across several purchases – your cost basis – the total invested, and your profit or loss at the current price.

$
Average price per share
$ —
Total shares
—
Total invested
$ —
Current value
$ —
Unrealised profit or loss
$ —
Return
— %

Averaging down – buying more after a price fall – lowers your average cost, so a smaller recovery is needed to break even. It only helps if the company’s prospects are still sound.

How to use the Stock Average Calculator

  1. Shares bought in each purchase
  2. Price paid in each purchase
  3. Current stock price

Results update as you type, and every field accepts the units shown in its menu.

How it works

Enter the number of shares and the price of each purchase (in the same order), and the current price.

Tips

  • Take figures from the same financial statements and the same fiscal year.
  • Compare ratios with companies in the same industry, not across industries.
  • Use several valuation measures together; no single ratio tells the whole story.
  • Market prices change every second – refresh the share price before you rely on a result.

Common mistakes to avoid

  • Mixing per-share figures with company totals.
  • Using trailing earnings for one company and forward earnings for another.
  • Forgetting dilution from options and convertible securities.

Inputs explained

Field What to enter
Shares bought in each purchase A list of numbers separated by commas, spaces or new lines
Price paid in each purchase A list of numbers separated by commas, spaces or new lines
Current stock price Amount in your currency

What each result means

  • Average price per share = dot([Shares bought in each purchase], [Price paid in each purchase])÷sum([Shares bought in each purchase])
  • Total shares = sum([Shares bought in each purchase])
  • Total invested = dot([Shares bought in each purchase], [Price paid in each purchase])
  • Current value = sum([Shares bought in each purchase])×[Current stock price]
  • Unrealised profit or loss = [Current value] – [Total invested]
  • Return = [Unrealised profit or loss]÷[Total invested]×100

Example values

How the main result changes when Current stock price changes and everything else stays at the example values above:

Current stock price Average price per share
52 103.08
78 103.08
104 103.08
130 103.08
156 103.08
208 103.08

Formula

Average price = Σ (shares × price) ÷ Σ sharesUnrealised profit = (current price − average price) × total shares

Worked example

Inputs — Shares bought in each purchase: 50, 30, 40; Price paid in each purchase: 120, 95, 88; Current stock price: $104.
Results — Average price per share = $103.08; Total shares = 120; Total invested = $12,370.00; Current value = $12,480.00; Unrealised profit or loss = $110.00; Return = 0.89 %.

Frequently asked questions

How do I calculate my average stock price?

Total amount paid ÷ total shares bought.

Should I include commissions?

Yes, for an accurate cost basis.

Does averaging down work?

Only if the stock recovers; it also increases your exposure.

What formula does the Stock Average Calculator use?

Average price = Σ (shares × price) ÷ Σ shares.

Cite this calculator

Speedy Calculator. (2026). Stock Average Calculator (Average Cost). Speedy Calculator. https://speedycalculator.com/calculators/finance/stock-average/