UK Crypto Tax Calculator
Use this free UK crypto tax calculator to estimate the gain on a disposal under HMRC's rules. It opens with the United Kingdom already selected, works in pounds, and applies a pooled cost basis the way a Self Assessment requires. Enter what you bought, what you sold and what you received; the estimate appears below. It is an estimate, not a return.
This calculator produces an estimate for general information, not tax advice, and covers one disposal at a time. UK treatment depends on your circumstances and on your full year of activity. Confirm your position with HMRC or a qualified adviser.
Estimate your crypto capital-gains tax
A quick estimate for a single disposal. No account needed, nothing you type leaves your browser.
List your purchase lots, oldest first.
The method changes the result only when you sell part of your holdings.
- Add a purchase lot: enter a quantity and unit cost.
- Enter the quantity you sold.
- Enter your sale proceeds (what you sold for).
Estimate only, not tax advice. Applies TY 2025/26 rules (snapshot June 2026) to a single disposal, and ignores income, losses elsewhere, wealth taxes and personal circumstances. Your filed figure comes from your full report.
How the UK crypto tax calculator works
The calculator above is already set to the United Kingdom, so you do not have to find it in the country list. Add a row for each acquisition of the token you sold, with the quantity, what you paid per unit and the date. Then enter the quantity you disposed of and the proceeds you received. The estimate is the difference between the proceeds and the cost the UK rules assign to those units.
That last part is the whole reason a UK-specific calculator exists. In most countries you can pick a method and the answer follows. In the UK you cannot: HMRC decides which acquisitions your disposal is matched against, and only what is left over draws from the averaged pool. A calculator that simply runs first-in-first-out over your purchases will give you a confident number that is wrong.
You can change the country at any time. If you landed here but file somewhere else, the picker is live rather than locked.
Section 104 pooled cost basis
Under Section 104 pooling, every unit you hold of a given token sits in one pool at an averaged cost. A disposal takes its cost from that average rather than from a specific purchase, and the pool continues with what is left. This is why the UK has no meaningful FIFO-versus-LIFO choice: you do not select a method, the pool decides.
Averaging is also what makes the arithmetic unforgiving across a real year. Every acquisition moves the average, so the cost of a disposal in November depends on a purchase in March that itself moved an average set in January. One acquisition left out shifts every disposal after it. For a single disposal the calculator above handles this fine; across a full year with several venues it is the reason people stop using spreadsheets.
Same-day and 30-day matching rules
Before anything reaches the pool, HMRC matches a disposal in a fixed order. The order is the rule, not a detail of it:
1. Same-day acquisitions
Acquisitions of the same token made on the day of the disposal are matched first, ahead of everything else you hold.
2. Acquisitions in the next 30 days
Then acquisitions made in the 30 days after the disposal, taken in order. This is the bed and breakfasting rule. Sell at a loss and buy back inside a month and the disposal is matched against that repurchase instead of your pooled cost, so most of the loss you were realising is not there. Unlike a US wash sale it is not disallowed, it is re-matched, which changes the number rather than rejecting it.
3. Whatever is left, from the Section 104 pool
Only the remaining quantity draws on the averaged pool. If you sold more than you had recently acquired, most of your disposal will land here.
The estimate above is a single-disposal view, so it will not see a repurchase you make next week. If you are selling and rebuying within a month, treat the figure as provisional and let CryptaTax apply the matching across your full history.
Applying the £3,000 capital gains allowance
The annual exempt amount is £3,000 for 2025/26 and 2026/27. It applies to your net gains for the whole tax year, across every chargeable asset, not to each disposal on its own. So the calculator deliberately does not subtract it from a single estimate: doing that would understate your position the moment you have a second disposal, and most people have several.
There is a second threshold that decides whether you must report at all rather than how much you owe: if your total disposal proceeds exceed £50,000 in the tax year you have a reporting requirement even when the gain sits inside the allowance. Both thresholds are covered in the UK crypto tax guide.
Basic vs higher rate: 18% and 24%
Above the allowance, capital gains are taxed at 18% if you are a basic-rate taxpayer and 24% if you are a higher- or additional-rate taxpayer. Those rates have applied since 30 October 2024.
Which band you fall into depends on your other income, which this calculator does not ask for and should not guess. Treat the gain as the output and apply your own rate to it. If your income sits near a band boundary, a gain can straddle the two, and that is a case worth taking to an accountant rather than a widget.
Income from staking, mining and airdrops
Earning crypto is a different tax altogether. Staking rewards, mining and most airdrops are income at their sterling value when you received them, taxed at your marginal income rate, and they belong on the main SA100 rather than in your capital gains.
The join between the two regimes is where estimates go wrong. That receipt value also becomes the cost base of the units you received, which then enter the Section 104 pool. If you enter reward units in the calculator above, enter them with the value they had at receipt as their cost, not zero — a zero cost taxes you a second time on income you have already declared.
From estimate to SA108 filing
An estimate settles a decision. A filing needs your full year, with every disposal matched in HMRC's order and every reward valued at receipt. Crypto reaches a UK return in two places: disposals on the SA108 Capital Gains Summary, in the cryptoassets section, and crypto income on the SA100 as miscellaneous income.
CryptaTax imports your exchanges and wallets, applies the same-day and 30-day rules before the pool automatically, and produces SA108-ready figures with each number traceable to the transaction behind it. Detail on the forms: Capital Gains Summary SA108 and the SA100.
Other crypto tax calculators and UK guides
Filing elsewhere? Try the Australian crypto tax calculator or the Canadian crypto tax calculator, or start from the main crypto tax calculator and pick any of the supported countries. For the UK rules in full, read the UK crypto tax guide; if you are moving off another tool, see the best Koinly alternative for HMRC reporting.
FAQ
Work out the gain on each disposal, then total them for the tax year. The gain is your proceeds less the cost HMRC assigns to the units sold, which means matching the disposal against same-day acquisitions first, then acquisitions in the next 30 days, then the Section 104 pooled average. Net gains above the £3,000 annual exempt amount are taxed at 18% or 24% depending on your income band.
Yes, and it needs no account. Enter your acquisitions, the quantity you sold and the proceeds, and the estimate appears on the page. It covers one disposal at a time; a full Self Assessment needs your whole year, which is what a CryptaTax report produces.
No, deliberately. The annual exempt amount applies to your net gains for the entire tax year across all chargeable assets, not to a single disposal. Subtracting it from one estimate would understate your position as soon as you have a second disposal. Total your gains for the year first, then apply the £3,000.
All units of the same token are held in one pool at an averaged cost, and a disposal draws its cost from that average rather than from a specific purchase. Every acquisition moves the average, so the cost of any disposal depends on everything you bought before it. The same-day and 30-day matching rules are applied first, and only the leftover quantity comes from the pool.
If you buy the same token back within 30 days of selling it, the disposal is matched against that repurchase instead of your pooled cost, so the loss you intended to realise largely disappears. It is a re-matching rather than a disallowance, so it changes the number rather than rejecting the loss outright. A single-disposal estimate cannot see a repurchase you have not made yet.
Often yes. Swapping one token for another, spending crypto and gifting it (other than to a spouse or civil partner) are all disposals, so a gain can arise without any sterling reaching your bank account. Reporting can also be required on proceeds above £50,000 even when no tax is due.