// by seankriegler.com

Stock Profit / Loss Calculator

Track multiple purchases of the same stock at different prices. Enter each lot separately to see per-lot P&L, your weighted average cost basis, and a visual breakdown of each position's contribution to your total gain or loss.

Current Market Price
Purchase Lots

Add a row per purchase. Bought at different prices? That's cost averaging — add each batch separately to see how each lot performs.

# Purchase Price Shares Cost Basis Current Value P&L ($) P&L (%) Weight
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Total Cost Basis
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Current Value
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Total P&L
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Total Return
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Avg Purchase Price
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Total Shares
Visual Breakdown

// Cost Basis

The total amount you paid across all purchase lots. This is your break-even reference — you need the current value to exceed this to be in profit.

// Average Purchase Price

Total cost basis ÷ total shares. When you buy more at lower prices you "average down" — bringing this number closer to the current price speeds up recovery.

// Lot Weight

Each lot's share of your total cost basis. A 40% weight means that lot represents 40% of your invested capital, so its performance has a proportionally larger impact.

// Unrealised P&L

The profit or loss you would make if you sold right now at the current price. It only becomes realised — and potentially taxable — when you actually sell.