Free UK crypto tax calculator — your Capital Gains Tax in seconds.
Upload your exchange CSV and see your full HMRC Capital Gains Tax figure on screen — free, no account, no API keys. Built on HMRC's same-day, 30-day and Section 104 rules. You only pay £49 per tax year when you download your SA108-ready report.
Drop your exchange CSV here
Binance, Coinbase, Kraken — or any file via quick column mapping.
or browse filesFrom CSV to your CGT figure, in three steps.
No account to see your number, no exchange logins, no waiting. Upload, read your figure free, and pay only if you choose to download the report you file.
Drop your CSV
Export from Binance, Coinbase, Kraken — or hand us any file and map the columns in seconds. Add as many exchanges as you trade on.
Your full figure, on screen
Proceeds, net gain and estimated Capital Gains Tax — with the Section 104 working shown. Up to 2,000 transactions, no charge, no account.
Your SA108-ready report
Box-by-box figures, a PDF, and the full CSV audit trail — ready to file or hand to your accountant.
£49 per tax yearThis calculator works from a CSV file you upload, not an API connection.We never ask for exchange logins or read/write keys — so there's nothing that could leak, and nothing that could ever move your funds. If a disposal is missing its cost basis, we flag the result provisionaland won't let you download a number we can't stand behind.
Crypto tax calculator questions, answered.
Is this crypto tax calculator really free?
Yes. You can upload your CSV (or type your trades in) and see your full UK Capital Gains Tax figure on screen with no account and no card. You only pay a flat £49 per tax year if you want to download the SA108-ready report to file — and that one fee includes every prior tax year.
Do I need to connect my exchange or wallet?
No — and we deliberately don't offer it. You bring a CSV export, or enter trades manually. We never ask for exchange API keys or wallet connections, so there is no access that could move your funds and nothing to revoke later. See our Binance, Coinbase and Kraken export guides.
How accurate is it?
Every figure is computed under HMRC's same-day, 30-day and Section 104 pooling rules, in the order HMRC applies them, and reconciled against HMRC's own published worked examples to the penny. We also cross-check the engine against the independent open-source BittyTax. You can open the working and check each disposal — see our methodology and Section 104 guide.
Which tax year does it calculate, and at what rate?
It calculates 2025/26 and prior years. For 2025/26 the Capital Gains Tax-free allowance is £3,000, and gains above it are taxed at 18% within your basic-rate band or 24% above it. Your rate depends on your other income — the full breakdown is in our 2025/26 rates guide.
Which exchanges does it support?
Direct CSV formats for Binance, Coinbase, Kraken and more. For anything else, drop the file and map the columns in a few seconds — if it lists your trades, the calculator can read it. It reads the shape of your data, not just specific column names, so an exchange tweaking its export rarely breaks it.
Does it handle staking, airdrops and NFTs?
The calculator works out your Capital Gains Tax on disposals. Staking and airdrops are usually Income Tax at the pound value when you receive them, then CGT when you later sell — see staking & airdrops. Each NFT is a separate asset taxed on disposal — see how NFTs are taxed.
How much does it cost to file?
A flat £49 per tax year — a one-off for that year, not a subscription — whatever your trade count, with every prior year included. You can read your number for free first and only pay when you download the report.
What do I actually download?
A filled-in SA108 — the Capital Gains summary pages of Self Assessment — as a PDF laid out box by box, plus the full CSV audit trail behind every number. Here's what each SA108 box means and how to report it.
Is this tax advice, or affiliated with HMRC?
Neither. CryptoCGT is an independent information tool that computes your figures from HMRC's published rules — it isn't HMRC software and it isn't tax advice. Review the numbers and your own circumstances before you file, and speak to an accountant if your situation is complex.
See your number in seconds.
Drop your CSV, read your full Capital Gains Tax figure free, and pay only if you download. No sign-up, no API keys.