jeremylongshore Calculating Crypto Taxes
Overview
Calculate cryptocurrency tax obligations from transaction history. Supports FIFO, LIFO, and HIFO cost basis methods, identifies taxable events (trades, staking, airdrops), and generates Form 8949 compatible reports.
DISCLAIMER: This tool provides informational calculations only, not tax advice. Consult a qualified tax professional.
Prerequisites
- Transaction history exported as CSV from your exchanges (Coinbase, Binance, Kraken, etc.)
- Python 3.8+ installed
- Understanding of your tax jurisdiction's crypto rules
Instructions
Prepare transaction data by exporting CSV from each exchange:
Exchange Export Location Coinbase Reports > Tax documents > Transaction history CSV Binance Orders > Trade History > Export Kraken History > Export Generic See ${CLAUDE_SKILL_DIR}/references/exchange_formats.mdfor column mappingRun basic tax calculation using FIFO (IRS default):
python ${CLAUDE_SKILL_DIR}/scripts/tax_calculator.py --transactions your_trades.csv --year 2025 # 2025 = tax yearCompare cost basis methods to understand tax implications:
python ${CLAUDE_SKILL_DIR}/scripts/tax_calculator.py --transactions trades.csv --compare-methodsMethods:
--method fifo(IRS default),--method lifo(Last In First Out),--method hifo(minimize gains)Generate Form 8949 report as CSV:
python ${CLAUDE_SKILL_DIR}/scripts/tax_calculator.py --transactions trades.csv --method fifo --year 2025 --output form_8949.csv --format csv # 2025 = tax yearHandle income events (staking, airdrops, mining, DeFi yield):
python ${CLAUDE_SKILL_DIR}/scripts/tax_calculator.py --transactions all_events.csv --income-reportConsolidate multi-exchange data into a unified report:
python ${CLAUDE_SKILL_DIR}/scripts/tax_calculator.py --transactions coinbase.csv binance.csv kraken.csv --year 2025 # 2025 = tax year
Output
Reports include short-term and long-term capital gains/losses broken down by transaction, with proceeds, cost basis, and gain/loss per disposal. Summary shows total proceeds, total cost basis, net capital gain, and short/long-term split. Income report lists staking, airdrop, and mining income with fair market values.
See ${CLAUDE_SKILL_DIR}/references/implementation.md for detailed output format examples.
Error Handling
| Error | Cause | Fix |
|---|---|---|
| Missing columns | CSV format mismatch | Verify format matches exchange template |
| Unknown transaction type | Unrecognized event category | Review and manually categorize |
| Insufficient lots | Missing buy transactions | Check for missing imports or transfers |
Examples
Basic FIFO tax calculation - Standard IRS-default method for a single exchange:
python tax_calculator.py --transactions trades.csv --year 2025 # 2025 = tax year
HIFO to minimize gains - Highest-cost lots disposed first to reduce taxable gain:
python tax_calculator.py --transactions trades.csv --method hifo --year 2025 # 2025 = tax year
JSON output for processing - Machine-readable export for tax software integration:
python tax_calculator.py --transactions trades.csv --format json --output tax_data.json
Verbose with lot details - See which specific lots were matched to each disposal:
python tax_calculator.py --transactions trades.csv --verbose --show-lots
Resources
- IRS Virtual Currency Guidance: https://www.irs.gov/businesses/small-businesses-self-employed/virtual-currencies
- Form 8949 Instructions: https://www.irs.gov/instructions/i8949
- CoinGecko API for historical prices
${CLAUDE_SKILL_DIR}/references/implementation.md- Detailed output formats, configuration, advanced usage