Does HMRC have its own capital gains tax calculator?

HMRC publishes tools for some situations, mainly property. They are accurate on the arithmetic and do not attempt the harder part, which is working out your acquisition cost across years of trades and transfers.

Can I use a capital gains tax calculator for crypto?

For the tax arithmetic yes, but only if you already trust the gain figure going in. Share pooling and the 30 day rule decide what a crypto gain is, and getting those wrong moves the number far more than the tax rate does.

What happens if I made a capital loss?

Losses reduce gains in the same tax year and then carry forward with no expiry. A loss only counts once you quantify it and notify HMRC, and you have four years from the end of that tax year to do it. Unreported losses are worth nothing.

Are capital gains tax rates different in Scotland?

Scotland sets its own income tax rates and bands, so the point where your basic rate band ends differs, which shifts the split between the 18% and 24% capital gains rates. Capital gains tax itself is UK wide.

Capital gains tax calculator

Q: How much capital gains tax will I pay?

On gains above your £3,000 annual exempt amount you pay 18% on whatever fits in the remainder of your basic rate band and 24% above that. Because the gain is stacked on top of your income, two people with identical gains and different salaries pay different amounts.

Work out what you owe on a disposal in the 2026 to 2027 tax year. Gains stack on top of your income, so the same gain can be taxed at 18% and 24% at once. This calculator splits it the way HMRC does instead of making you pick one rate.

Works for cryptoassets, shares, funds, second properties and land.

Two sheets of accounting paper with a brass ruler and navy pencil, showing a rising line and a ruled grid

Your taxable income this year, before the gain

Salary, self employed profit, rent, pension and dividends. This decides how much of your gain falls in the 18% band, so it changes the answer more than people expect.

Total gains from all disposals

Sale proceeds minus what you paid, minus allowable costs such as fees and commission. Do not deduct losses here, there is a field for those.

Losses you are offsetting

Losses from this year, plus any carried forward that you have already notified to HMRC. Unreported losses do not count.

Have you used your £3,000 allowance elsewhere this year?

The annual exempt amount is one allowance across every asset you dispose of, not one per asset.

Read this before you rely on the number. It assumes England, Wales or Northern Ireland rates, one tax year, and that your gain qualifies for neither Business Asset Disposal Relief nor Private Residence Relief. It does not apply share pooling, the same day rule or the 30 day rule, which routinely change a crypto or share gain by more than the tax itself. Treat it as a sanity check on a figure you already have.

Your estimate

2026 to 2027 tax year, capital gains tax only

Enter your income and your gains to see the calculation.

How the calculation works

Start with the gain. That is what you sold it for, minus what you paid, minus costs you were allowed to deduct along the way. Broker commission, exchange fees, stamp duty on the original purchase, legal and estate agent fees on a property. People leave these out and hand HMRC more than they owe.

Then take off losses, then the annual exempt amount, which is £3,000 for individuals and does not roll over into next year. What survives is your taxable gain.

Now the part most calculators skip. Your gain is stacked on top of your income, not taxed separately. Whatever is left of your basic rate band, which runs to £50,270, gets taxed at 18%. Everything above it goes at 24%. Earn £40,000 and make a £30,000 gain and you will pay both rates on the same disposal.

That is why the tool asks for your income. A calculator that makes you choose between basic and higher rate is answering a simpler question than the one HMRC asks.

Where an estimate stops being enough

The arithmetic above is the easy half. The hard half is deciding what your gain actually was, and there are three places this tool cannot help.

Matching rules. With shares or cryptoassets you do not choose which units you sold. Anything bought the same day is matched first, anything bought in the next 30 days comes second, and only then does the rest come out of your pooled average cost. HMRC sets this out for cryptoassets from CRYPTO22250 onwards. Sell at a loss and buy back within a month and the loss you were counting on gets absorbed into the new holding.

Reliefs. Private Residence Relief, Business Asset Disposal Relief at 18%, gift holdover, spouse transfers. Any one of them can change the answer to nothing owed at all, and none of them apply automatically.

Deadlines. Sell UK residential property and you have 60 days from completion to report and pay, separate from your tax return. Miss it and interest and penalties follow. Everything else goes through Self Assessment.

If your number comes from crypto software, treat it as a first draft. Missing acquisition data gets recorded as a zero cost, which taxes the whole proceeds as gain, and wallet transfers between your own addresses get logged as sales that never happened. Our reconciliation service exists because of exactly that, and the capital gains tax accountant page covers how we handle the rest.

Questions about the calculation

How much capital gains tax will I pay?

On gains above your £3,000 allowance, 18% on whatever fits in the rest of your basic rate band and 24% above that. Because the gain sits on top of your income, two people with identical gains and different salaries pay different amounts.

Does HMRC have its own calculator?

HMRC publishes tools for some situations, mainly property. They are accurate on the arithmetic and do not attempt the hard part, which is working out your acquisition cost across years of trades and transfers.

Can I use this for crypto?

For the tax arithmetic, yes. For the gain itself, only if you already trust the figure going in. Pooling and the 30 day rule decide what a crypto gain is, and getting those wrong moves the number far more than the rate does.

What if I made a loss?

Losses reduce your gains in the same year, then carry forward with no expiry. A loss only counts once you quantify it and tell HMRC, and you have four years from the end of that tax year to do it. Unreported losses are worth nothing.

Are Scottish rates different?

Scotland sets its own income tax rates and bands, so where your basic rate band ends differs, which shifts the 18% and 24% split. Capital gains tax itself stays UK wide. This tool uses the England, Wales and Northern Ireland thresholds.

Not sure the gain is right?

Most of the money is won or lost before the rate is applied. Send us the figures and we will tell you whether they hold up.

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