Calculating crypto profit and loss (P&L) is essential for tracking portfolio performance, filing tax returns, and making informed trading decisions. The basic concept is simple, but multiple purchases at different prices, trading fees, and the distinction between realised and unrealised gains add complexity.
The basic P&L formula
Profit or Loss = (Current Price - Entry Price) x Quantity - Fees
If the result is positive, you have a gain. If negative, a loss.
Worked example: single purchase
You buy 0.5 BTC at $40,000 per coin. The current price is $52,000.
| Component | Value |
|---|---|
| Entry price | $40,000 |
| Quantity | 0.5 BTC |
| Cost basis | $20,000 |
| Current value | $26,000 |
| Unrealised profit | $6,000 (30%) |
If you sell at $52,000 and pay a 0.1% trading fee ($26 on $26,000), your realised profit is $5,974.
Multiple purchases at different prices
Most investors accumulate crypto over time at varying prices. You need to calculate the average cost basis.
| Purchase | Quantity | Price | Cost |
|---|---|---|---|
| Buy 1 | 0.3 BTC | $35,000 | $10,500 |
| Buy 2 | 0.2 BTC | $42,000 | $8,400 |
| Buy 3 | 0.5 BTC | $38,000 | $19,000 |
| Total | 1.0 BTC | $37,900 |
Average cost basis = $37,900 / 1.0 = $37,900 per BTC.
If the current price is $45,000, your unrealised profit is $45,000 - $37,900 = $7,100 (18.7%).
Realised vs unrealised gains
| Type | Definition | Tax impact |
|---|---|---|
| Unrealised gain | Profit on positions you still hold | Not taxable (in most jurisdictions) |
| Realised gain | Profit from positions you have sold | Taxable in the year of sale |
| Unrealised loss | Loss on open positions | Not deductible |
| Realised loss | Loss from sold positions | Can offset gains |
You only lock in a gain or loss when you sell, swap, or otherwise dispose of the asset. Simply holding an asset that has increased in value does not create a taxable event in most countries.
Accounting for fees
Crypto trading fees reduce your profit and increase your loss. Include all relevant costs:
- Trading fees (maker/taker fees, typically 0.05% to 0.5%)
- Network fees (gas fees for on-chain transactions)
- Withdrawal fees (charged by exchanges for transferring to external wallets)
- Spread (the difference between buy and sell prices on the exchange)
Always add purchase fees to your cost basis and subtract sale fees from your proceeds.
Percentage return calculation
Return (%) = ((Current Value - Total Cost) / Total Cost) x 100
This gives a clear picture of performance regardless of the absolute amounts invested.
Tracking P&L across multiple assets
For a portfolio with multiple cryptocurrencies, calculate P&L for each asset individually, then sum them for total portfolio P&L.
| Asset | Cost basis | Current value | P&L | Return |
|---|---|---|---|---|
| BTC | $20,000 | $26,000 | +$6,000 | +30.0% |
| ETH | $10,000 | $8,500 | -$1,500 | -15.0% |
| SOL | $5,000 | $7,200 | +$2,200 | +44.0% |
| Total | $35,000 | $41,700 | +$6,700 | +19.1% |
Common mistakes
- Forgetting fees. Trading fees add up, especially for frequent traders. A 0.2% fee on each buy and sell effectively reduces returns by 0.4% per round trip.
- Ignoring crypto-to-crypto swaps. Swapping BTC for ETH is a taxable event in most jurisdictions. The swap realises a gain or loss on the BTC position.
- Using the wrong cost method. FIFO, LIFO, and average cost produce different P&L figures. Use the method required or accepted in your tax jurisdiction.