First, convert the value of your airdrops, promos, and rewards to US dollars (USD) if the issuer or exchange hasn't already done this for you.
You can use an online cryptocurrency converter, such as CoinMarketCap, to determine the USD value based on either the historical close price or the average price (doesn't matter which one you choose, as long as you stay consistent throughout your calculations). Be sure to keep notes of your calculations with your tax records in case it's ever questioned.
Example: Let's say you received .000027762 BTC as a promo on December 9, 2021, and you were able to immediately exercise control over it (sell, trade, exchange, etc.).
- On that day, CoinMarketCap reports that the BTC close price was $47,672.12.
- Multiply the quantity received by the close price (.000027762 × $47,672.12 = $1.32 rounded).
- Repeat this calculation for all airdrops, promos, and staking rewards received in 2021, based on the close price of the day you were able to exercise control over them.
- Add them together for one total sum, and move on to the next section.