# What is the outbound fee on THORChain?

The outbound fee is what THORChain charges to pay the gas for the last step of a swap, the transaction that delivers the coin on its destination chain. It is taken from the swap output, so the amount you receive is after the fee.

Also called outbound gas.

## What it pays for

To deliver the final coin, THORChain pays the gas on the destination chain and charges the outbound fee from the swap output. The fee covers that gas and the protocol’s overhead.

In THORChain’s own example of a BTC to ETH swap, the outbound fee is paid in ETH, the coin you receive.

## How it is calculated

- The base is the gas on the destination chain, which is the cost of the transaction that delivers the coin there.
- THORChain multiplies that gas by a dynamic outbound fee multiplier, which moves between 1 and 3 with network and protocol conditions.
- The fee therefore rises and falls with the destination chain’s gas price, so the same swap can cost more or less at different times.

## Where it fits in the cost of a swap

THORChain’s swapper documentation says the cost of a swap has two parts, the outbound fee and price slippage.

Sending the coins in costs a separate fee on the source chain, and that fee goes to the miners or validators of the source chain.

## In Redacted

When you send a coin to its own chain, the app pays it out through THORChain from a fresh payout account. Redacted’s fees page says the networks underneath have costs of their own and that Redacted doesn’t change them, and the outbound fee is one of those costs.

More: [Reserve and Spending](https://redacted.gg/docs/using-redacted/how-it-works.md)

## Related terms

- [Native cross-chain swap](https://redacted.gg/glossary/cross-chain-swap.md): A native cross-chain swap trades a coin on one chain for a coin on another, for example Bitcoin for Ether, by moving the real coins between vaults instead of minting wrapped copies on a bridge.
- [Secured assets](https://redacted.gg/glossary/secured-assets.md): Secured assets are native coins deposited into THORChain’s vaults and held one to one on THORChain, such as BTC-BTC for Bitcoin. Apps use them for trading, lending and more, and they can be withdrawn back to their home chain as the real coin.
- [Price limit](https://redacted.gg/glossary/price-limit.md): A price limit is the least amount of a coin you accept back from a swap, written into the memo. If the swap would pay less than that, THORChain refunds your coins instead of filling the swap below the limit.
- [Streaming swap](https://redacted.gg/glossary/streaming-swap.md): A streaming swap cuts one large swap into smaller sub-swaps that run over several blocks, so each piece moves the price less. You choose the interval between pieces and how many pieces there are.
- [THORChain](https://redacted.gg/glossary/thorchain.md): THORChain is a network that swaps native coins across chains, such as Bitcoin for Ether, with no bridges and no wrapped tokens. The coins sit in vaults on their home chains, secured by about 100 independent node operators.

Sources: [Fees, THORChain documentation](https://docs.thorchain.org/technical-documentation/technical-deep-dive/fees), [Swappers, THORChain documentation](https://docs.thorchain.org/technical-documentation/understanding-thorchain/roles/swapping)
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Page: https://redacted.gg/glossary/outbound-fee/