Crypto Profit/Loss Calculator
Calculate crypto profit, loss, and capital gains tax liability.
What this calculator does
This calculator works out what a cryptocurrency holding genuinely made or lost, after the fees exchanges take on both sides of a trade. Enter your total cost, the value now or on disposal, and how long you held it.
It returns the gain or loss in pounds, the return as a percentage of what you committed, and an annualised rate. That last number carries unusual weight in crypto, because holding periods are often measured in weeks — a 40 percent gain over two months is an entirely different proposition from 40 percent over four years.
When to use it
The obvious use is after closing a position, to see the real figure rather than the fee-free number most exchange apps display. It also helps before disposing, so you can size the gain against your remaining CGT annual exempt amount for the tax year.
There is a compliance use as well. Because HMRC treats each disposal separately, and because the section 104 pooling rules mean your cost is an average rather than a specific purchase, working through individual disposals here gives you figures to sanity-check against whatever your exchange or tax software produces.
Understanding the inputs
Purchase price should be your full acquisition cost in sterling: quantity times price paid, plus exchange trading fees and any network fee incurred acquiring or transferring the tokens. These are allowable costs and reduce the eventual taxable gain.
Current or exit value is the sterling value today, or your net proceeds after disposal fees. If you bought or sold in another currency, convert at the rate on the transaction date rather than today's rate. Holding period drives the annualised figure and takes decimals, so five months is roughly 0.42.
How is this calculated?
Gross Profit = (Sell Price − Buy Price) × Quantity. Net Profit = Gross − Fees. Tax Owed = Net Profit × Tax Rate.
A worked example
Suppose you bought 2.5 ETH at £1,480, a cost of £3,700, and sold eighteen months later at £2,240 each, giving proceeds of £5,600. Exchange fees across both trades came to £42.
Gross gain is £1,900 and net of fees £1,858 — a return of 50.2 percent on £3,700, or roughly 31 percent annualised. Unlike the US, the holding period does not change the tax rate here: what matters is whether the £1,858 fits within your CGT annual exempt amount, which after recent reductions it may well not.
Limitations and assumptions
Crypto is among the most volatile assets available to UK retail investors. Past returns do not predict future ones, and this calculator assumes one flat return with no volatility, so it cannot express that these assets have repeatedly fallen 70 percent or more and that individual tokens have become worthless.
It does not model staking rewards, airdrops, forks, DeFi lending, or the section 104 pooling and 30-day matching rules that govern real HMRC calculations. Crypto exchanges are largely outside FCA protection, so there is no compensation scheme if one fails. This is not investment or tax advice.
Common Questions
- How is crypto profit calculated?
- Gross profit is sale price minus purchase price, multiplied by the quantity held. Deduct exchange fees on both sides to reach net profit, then divide by your total cost for a return percentage. Transaction and network fees form part of your allowable costs when calculating the gain for HMRC.
- How does HMRC treat cryptocurrency?
- For most individuals, as an asset subject to capital gains tax rather than income tax. Each disposal — selling for pounds, exchanging one token for another, or using crypto to pay for something — is a CGT event. Gains above the annual exempt amount are taxable at the rate for your income band.
- Do I pay tax when swapping one token for another?
- Yes. HMRC treats a token-for-token exchange as a disposal of the first asset at its sterling market value on that date, crystallising a gain or loss even though no pounds reached your bank account. Active traders are frequently caught out by this and end up with tax due on paper gains.
- What are the pooling rules for crypto?
- HMRC applies share matching rules. Disposals match first against acquisitions on the same day, then against acquisitions in the following 30 days, and only then against the section 104 pool, which holds a running average cost for all remaining units of that token. This is quite different from the US FIFO default.
- How is staking income taxed?
- Staking and mining rewards are generally treated as miscellaneous or trading income at their sterling value when received, depending on the scale and organisation of the activity. That value becomes the acquisition cost of the tokens, and any later change in value is dealt with under CGT on disposal.
- Can crypto be held in an ISA?
- No. Cryptocurrency itself cannot be held in a Stocks and Shares ISA. Certain exchange-traded products with crypto exposure have become available to UK retail investors and some may be ISA-eligible, but direct holdings on an exchange sit entirely outside any tax wrapper and are fully exposed to CGT.
- Can I claim relief for crypto losses?
- Yes. Capital losses on crypto disposals offset gains in the same tax year, and unused losses can be carried forward indefinitely provided you report them to HMRC within four years of the end of the relevant tax year. Claiming losses in a bad year is often worth the paperwork.
- What if I lose access to my wallet?
- HMRC's position is that losing a private key is not itself a disposal, since the asset still exists. You may be able to make a negligible value claim if you can show the tokens have become worthless and are irrecoverable, but the bar is high and the claim needs proper evidence.
- How volatile is crypto compared with equities?
- Substantially more. Bitcoin has fallen more than 70 percent from prior peaks on several occasions and many smaller tokens have gone to zero. Annualised volatility commonly runs several times that of the FTSE All-Share. Any figure this calculator produces represents one path through an exceptionally wide range of outcomes.