Finance Calculators

Stock Average Calculator

Calculate the average cost basis of stock shares. The estimate updates in your browser as you type.

Average cost per share $47

What this tool is for

Stock Average Calculator supports personal finance review in finance calculators by showing how apply the formula shown on this page to the entered values. The page keeps the inputs, formula, and example together so the calculation can be checked before the number is reused.

When to use it

Use it when buy price 1, shares 1, and buy price 2 are already known and you need a quick estimate before comparing options, checking a worksheet, or copying the result into another workflow.

Inputs

  • Buy price 1 is the money value used by the formula. Use $ for this field.
  • Shares 1 is one of the direct inputs used to calculate stock average.
  • Buy price 2 is the money value used by the formula. Use $ for this field.
  • Shares 2 is one of the direct inputs used to calculate stock average.

Formula

average cost = (p1 x s1 + p2 x s2) / (s1 + s2)

Example

10 shares at $50 and 15 at $45 gives $47 average.

What the result means

The result labeled "Average cost per share" is the direct output of average cost = (p1 x s1 + p2 x s2) / (s1 + s2). In the worked example, 10 shares at $50 and 15 at $45 gives $47 average.

Before you rely on the result

This is educational math, not financial, tax, legal, or investment advice. Confirm important numbers with a qualified professional.

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Frequently asked questions

What does Stock Average Calculator calculate?

Stock Average Calculator uses average cost = (p1 x s1 + p2 x s2) / (s1 + s2) to calculate average cost per share from buy price 1, shares 1, and buy price 2.

Can I use this result as a final decision?

Stock Average Calculator is meant for fast planning math. Confirm taxes, contracts, school rules, medical guidance, building codes, or financial advice with the right source when the result affects a real decision.