FIFO or specific-ID cost basis for a stock sale.
Covers: cost basis, fifo, specific identification, lots, capital gains, shares.
Open the Cost-Basis Lot Picker tool →When you sell part of a position you bought at different prices, which shares you sell changes your taxable gain. Two methods: FIFO sells your oldest lots first (the broker default), while specific identification lets you choose exactly which lots go, often to harvest losses or favor long-term shares. A harvested loss is only real if you stay out of the security: buying the same or a substantially identical one within 30 days either side of the sale disallows the loss under the wash-sale rule (IRC §1091), which moves it into the basis of the replacement shares instead. Enter each lot's shares, cost per share, and whether it's long-term (held more than one year), then a sale price.
We split the realized gain into short-term (taxed as ordinary income) and long-term (the preferential capital-gains rate), because the character matters as much as the amount. Feed the result into the Capital Gains tile to see the tax. Pure arithmetic on your numbers: confirm your broker's basis records, especially after splits or reinvested dividends.
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