ETH gas fee calculator: how much have you spent this tax year?
Paste a wallet address to estimate gas spend in GBP for the current UK tax year on Ethereum, Arbitrum, Optimism, Base or Polygon. Review the underlying transactions separately to establish which fees are allowable for tax.
For informational purposes only. Not tax advice. Figures are approximate.
HMRC: which of this gas is deductible?
Allowable disposal fees reduce the gain. Section 38 TCGA 1992 permits specified acquisition and disposal costs. Whether a gas fee qualifies depends on what the transaction did; a total gas bill is not an allowable-cost total.
Allowable acquisition fees increase the cost basis. They add to the cost of the acquired asset. The relevant same-day, 30-day and Section 104 matching rules determine when that cost is used against a disposal.
A wallet transfer is not automatically a deductible cost. Where you retain beneficial ownership of the same asset, moving it between your wallets is not itself an acquisition or disposal. Check which asset and transaction any fee relates to, and do not deduct the same cost twice.
Read HMRC’s allowable-expenses guidance (CRYPTO22150) and valuation guidance (CRYPTO23000). Keep the fee evidence and valuation method with your records.
Gas fees and UK tax: common questions
Can gas fees reduce my UK capital gain?
Allowable acquisition fees increase the acquisition cost: a £100 purchase plus a £2 allowable acquisition fee has a £102 acquisition cost. Allowable disposal fees reduce the gain on a sale or swap. A fee relating to both an acquisition and a disposal needs a just and reasonable allocation and must not be deducted twice. Not every network fee qualifies; check the purpose of the transaction under HMRC CRYPTO22150.
Does this tool show all my gas costs?
It estimates gas for outbound transactions returned for one public address on one chain and does not determine your allowable tax deduction. Provider coverage and the free-tool limits can leave history incomplete. Fees paid by another wallet or a sponsor are not included. Reconcile the estimate with your transaction records before using it for tax working.
Why is the GBP figure approximate?
The tool uses available historical GBP prices and reuses a price for transactions on the same day, rather than obtaining an exact execution-time GBP quote for every fee. Missing transaction details or prices can leave costs out. HMRC CRYPTO23000 requires reasonable care, an appropriate transaction valuation and a consistent methodology; keep evidence of the method and values you use.
Which chains does this tool cover?
Ethereum, Arbitrum, Optimism, Base and Polygon. Choose one chain for each check. Gas is valued using the price of that chain’s native gas asset, so run the tool separately for each chain you used.
How far back does the tool go?
The current UK tax year, from 6 April to today. It does not calculate a previous year’s gas costs or prepare a tax return. Import the relevant historical records into your full tax working when preparing an earlier year.
Do I need to connect or sign with my wallet?
No. You paste a public address so the tool can read public blockchain records. It does not request private keys, a wallet connection or a signature.
Review fees alongside your crypto tax working
Import supported history into ChainTax to inspect classifications, matching and fee evidence. Resolve missing records and uncertain treatment before relying on the tax report.