What a BTC-to-ETH Swap on THORChain Costs in 2026

A BTC-to-ETH swap on THORChain has no fixed 2026 price: its cost combines Bitcoin’s inbound network fee, a liquidity-sensitive swap fee, Ethereum’s outbound fee and any affiliate charge. The swap passes through the BTC and ETH liquidity pools against RUNE; the amounts available in those pools, the trade size and the chosen execution speed affect the output. A current quote is the useful estimate because it simulates the route and itemises its fee components. For a fuller explanation of the route mechanics, see thor swap.

How does THORChain route BTC to ETH?

THORChain routes the swap through RUNE, first exchanging native BTC for RUNE and then RUNE for native ETH. It is a two-pool swap, not a direct BTC/ETH pool trade. The BTC is sent to a THORChain inbound address; after the network observes and processes it, ETH is sent from a vault to the destination address.

Each pool’s reserves determine the exchange rate and price impact. The larger the trade relative to pool depth, the more it shifts the pool balance and the larger the slip-based liquidity fee can be. The two pool legs contribute to the total execution cost. A quoted output therefore reflects more than the spot BTC-to-ETH price: it also reflects the amount moving through both pools and the settings used for execution.

Which fees make up the estimate?

There are four possible charges to account for, but they are paid or deducted at different points in the swap. The Bitcoin inbound fee is paid by the sending wallet to Bitcoin miners. THORChain deducts the liquidity fee from swap output. The Ethereum outbound fee covers sending the final ETH and is deducted from that output. An interface may also specify an optional affiliate fee, generally taken from the swap amount in the output asset.

• Inbound gas: Bitcoin transaction cost, paid separately from the swap output.
• Liquidity fee: determined by trade size and pool depth, subject to the applicable minimum fee floor.
• Outbound fee: deducted for delivery on Ethereum; its estimate changes with network gas costs and protocol parameters.
• Affiliate fee: applies only if the interface includes one in the swap.

The swap quote reports fees in an asset denomination, typically the destination asset, while the Bitcoin inbound charge is paid in BTC. To compare the full cost against the amount sent, convert the charges into a common unit and include the wallet’s Bitcoin fee. Do not treat a quote’s output-side “total” as the full BTC-denominated cost if it excludes that wallet-paid inbound charge.

How can you estimate the fee before sending?

Request a fresh quote for the intended BTC amount, ETH destination address and execution settings, then read the itemised fees alongside expected output. The THORChain quote endpoint simulates the swap and supplies fields such as liquidity, outbound and affiliate fees, total fees, slippage and quote expiry. Some interfaces expose the same breakdown in their confirmation screen.

For a meaningful estimate, use the exact amount and destination you plan to send. A different amount changes pool impact; a different destination chain or asset changes outbound costs. Check whether the interface has added an affiliate fee and whether it has selected streaming execution. Quotes are time-sensitive: pool balances and network gas can move, so refresh before signing and do not send after the quote expires.

The input size matters especially on shallow pools. A small trade may have modest slip but still be dominated by fixed network costs. A larger trade can spread fixed costs over more value while increasing liquidity fees through price impact. There is no reliable percentage that applies to every BTC-to-ETH swap.

When does streaming change the cost?

Streaming swaps divide a trade into smaller sub-swaps over time, allowing arbitrageurs to rebalance pools between executions. This can reduce price impact and the liquidity fee for a large trade compared with processing it rapidly as one swap. It does not remove Bitcoin’s inbound transaction or Ethereum’s final outbound transaction, and it takes longer to complete.

Use the quote’s streaming settings and expected duration to compare the output with a rapid execution. The better choice depends on how much the reduction in slip is worth against the delay and exposure to changing market prices. If the swap has a minimum-output limit and execution cannot meet it, the swap can be refunded; a refund may still require an outbound transaction on the source chain, with its associated fee.

Fee floors also matter when pool-based slip is low. THORChain’s minimum liquidity fee can depend on the route and, for eligible affiliate and pair combinations, a dynamic floor. That means two interfaces quoting the same assets and amount may not show identical fees if their affiliate configuration differs. A current quote—not a network-wide headline rate—is the relevant estimate.

For most users, the practical method is to compare fresh quotes for the same BTC amount and destination, include the wallet’s Bitcoin fee, and judge the result by expected ETH received. The cost is the combined effect of pool depth, gas, fee-floor rules, execution settings and any interface charge; without those live inputs, a precise 2026 BTC-to-ETH fee figure would be misleading.