This application is capable of computing short term and long term capital gains based on first-in, first-out (FIFO) accounting. The functionality is not limited to Bitcoin exclusively, but it can be used for any asset class or cryptocurrency. It can also identify disallowed losses known as a Wash sale. The Get Model Sample Data option below will demonstrate the wash sale example provided in the referenced Wikipedia article.

For traditional tax accounting with IRS Form 8949 (Sales and Other Dispositions of Capital Assets), there is an expectation that shares of a stock are sold in whole units. When dealing in Bitcoin, however, it is extremely common to buy and sell in partial units. For this reason, I group all transaction history by sale dates. From each sale it is possible to identify each of the values for boxes 1(a) through 1(h) on Form 8949. A single Bitcoin purchase may appear in more than one line on this form because multiple partial sales were performed to fully deplete the initial supply.

Example: Some time ago you bought 80 shares of XYZ at $50. The stock has declined to $30, and you sell it to take the loss deduction. But then you see some good news on XYZ and buy it back for $32, less than 31 days after the sale. You can't deduct your loss of $20 per share. But you add $20 per share to the basis of your replacement shares. Those shares have a basis of $52 per share: the $32 you paid, plus the $20 wash sale adjustment. In other words, you're treated as if you bought the shares for $52. If you end up selling them for $55, you'll only report $3 per share of gain. And if you sell them for $32 (the same price you paid to buy them), you'll report a loss of $20 per share.