Every action on a blockchain consumes computation, and gas is the unit that meters it. A plain transfer is cheap to verify; a swap that reads several pools, checks balances and moves two tokens costs more. The fee in your wallet is that computation, priced at whatever the network charges right now.
How is a gas fee calculated?
The formula is gas used times gas price. Gas used measures work: a plain ETH transfer costs exactly 21,000 gas, fixed by Ethereum's protocol rules, while a token swap commonly runs five to 10 times that, depending on how many pools the route touches. Gas price is what the market pays for block space at that moment, quoted in gwei, one billionth of an ETH.
Since Ethereum's EIP-1559 upgrade, the price has two parts. The base fee is set by the protocol from how full recent blocks were, and it is burned: destroyed, not paid to anyone. The priority fee is a tip to the validator for including your transaction sooner. Your wallet estimates both before you sign, and what is not used is not charged.
- Base fee
- Set by the protocol from block fullness and burned on payment. It moves at most 12.5% from one block to the next.
- Priority fee
- Your tip to the validator. Higher tips buy earlier inclusion when blocks run full.
- Gas used
- The computation the transaction actually consumed: 21,000 for a plain transfer, more for swaps.
- Total fee
- Gas used times the sum of base and priority fee, paid in the network's native token.
Put the pieces together and the numbers get concrete. At one gwei, a 200,000 gas swap costs 0.0002 ETH, about 60 cents with ETH at $3,000. At the 200 gwei of the 2021 peak, the identical swap cost $120. Same computation, thousandfold different price: gas fees are a market, not a constant.
Why does a swap cost more gas than a transfer?
A transfer updates two balances and is done. A swap calls a pool contract, which checks reserves, computes the output, updates its own accounting and moves two tokens; a routed swap can do that across several pools in one transaction. More computation means more gas used, which is why route optimizers weigh the gas of touching an extra venue against the rate it adds, and skip the venue when it does not pay for itself.
Why do gas fees spike?
Block space is a fixed-size auction that clears about every 12 seconds on Ethereum. When demand jumps, the base fee climbs by up to 12.5% per full block, and that compounds fast: six consecutive full blocks, a bit over a minute, are enough to double it. Congestion pricing is deliberate: it is how the network decides who goes first when everyone wants in.
The range across market cycles is enormous. At the 2021 peak, average gas prices ran above 200 gwei and a single swap could cost $50 or more. After the Dencun and Pectra upgrades moved most retail activity onto cheaper layer-2 networks, averages fell to about one gwei through 2025 and 2026, per YCharts, and a typical mainnet transaction in 2025 cost roughly $0.10 to $0.30.
Layer-2 networks change the math by batching: they bundle many transactions and settle them to Ethereum together, so hundreds of swaps share one set of mainnet costs. That is why the same swap that costs dollars on mainnet at peak hours can cost under a cent on a layer-2.
Do you pay gas on a 1inch swap?
It depends on how the swap fills, so here it is precisely. In the default intent-based mode you do not send a transaction at all: you sign an order, and a professional market participant called a resolver submits the on-chain transaction that fills it and pays that transaction's gas. That is why the interface shows zero swap gas fees, and why you can swap without holding the network's native token.
The network cost does not vanish; resolvers compete for orders and account for gas inside the rates they fill at. What changes is that you stop managing it: no gas token to top up, no fee settings to tune, no fee spent on a failed attempt. Prefer to submit transactions yourself? The Pro interface gives you that direct mode, gas controls included, and you pay the network like any on-chain action. Either way, none of the gas goes to 1inch: it pays the network.
The no-native-token property extends beyond plain swaps: cross-chain swaps and limit orders on 1inch also settle without you funding gas on the source or destination network. Estimated network costs are visible before you confirm anything, so the decision stays in front of you rather than buried in a wallet popup.
How can you pay less for the same swap?
- 1
Swap when the network is quiet
The base fee tracks live demand, and off-peak hours are routinely several times cheaper than busy ones. Gas trackers and most wallets show the current price.
- 2
Let a resolver carry the gas
Intent-based swaps on 1inch add no separate gas payment from your wallet; the route's cost is already reflected in the quote you accept.
- 3
Replace approvals with signatures
Token approvals are transactions too. Where a token supports permit signatures, one signed message replaces the separate approval transaction and its fee.
- 4
Pick the network deliberately
The same pair often has liquidity on several networks, and layer-2 fees commonly sit under a cent. Cross-chain swaps move assets across 13+ networks without a separate bridge.
What should you read next?
Gas is one of the two costs of a swap; the rate itself is the other. Read what slippage is and what a DEX aggregator does, or browse all Learn guides.
Frequently asked questions
Gas prices computation, not value: moving $10 costs the same work as moving $10,000. Small swaps on mainnet during busy hours can cost more in fees than they move. A layer-2 network, a quieter hour or an intent-based swap changes that math.
Not in the default intent-based mode: the resolver pays the transaction's gas, so a wallet holding only the token you are selling can still swap it. The same goes for cross-chain swaps and limit orders. Submitting transactions yourself in the Pro interface does require the native token.
Under EIP-1559, the base fee is burned, permanently removing that ETH from supply, and the priority fee goes to the validator who included your transaction. None of it goes to 1inch.
The base fee reprices every block, roughly every 12 seconds, so any estimate tracks a moving target. What you confirm is a maximum: if the network turns out cheaper, the difference is not charged.
Swap without managing gas at all
Intent-based swaps on 1inch need no native gas token: sign the order, and a resolver carries the transaction.
