Josh Liljenquist

Financial calculator

Stock Average Calculator

Calculate total shares, modeled cost basis, and weighted average cost per share from up to 100 purchase lots.

By •

Enter stock purchase lots

Purchase lot 1

Purchase lot 2

Enter values and select Calculate.

Stock-lot weighted average

Each lot cost is shares × price plus its entered fee. Total modeled cost divided by total shares gives weighted average cost per share.

Cost-basis boundary

This stock-lot workflow is distinct from a generic weighted average. It does not fetch prices, apply tax-lot rules or wash sales, provide official brokerage basis, or recommend averaging down.

Worked example

The editable example inputs above demonstrate the calculation and expose the assumptions used in every displayed result.

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This browser-local calculator provides an educational planning estimate, not financial, lending, tax, vehicle-valuation, brokerage, or investment advice.