Gas fees explained for a first Ethereum or layer 2 wallet withdrawal

05 September 2026

You buy $100 of ETH on Coinbase. You hit withdraw. The screen shows a network fee of $12. That is 12% of your purchase. This is gas, and it feels wrong.

Gas is the fee paid to process a transaction on Ethereum. The network is busy. Every transfer, swap, or contract call competes for space in the next block. Miners (now validators) pick transactions offering higher fees. Simple supply and demand.

Breaking down the fee: gwei, gas limit, base + priority

Ethereum fees have two parts under the EIP-1559 system introduced in 2021: a base fee and a priority fee (tip).

The base fee is the minimum required to get your transaction included. It is burned - destroyed, sent to nobody. It adjusts per block based on network congestion. Busy network = higher base fee. The priority fee is what you add to speed things up. Validators keep this.

So where does "gwei" come from? Gwei is a tiny denomination of Ether. One ETH equals 1,000,000,000 gwei. Fees are quoted in gwei per unit of computational work.

That unit of work is gas. Simple ETH transfers require 21,000 gas. A swap on a decentralized exchange might need 150,000 gas or more. Smart contract interactions, especially complex ones, cost more.

Your total fee formula: gas units × (base fee + priority fee) in gwei. Coinbase shows the total in dollars. That $12 fee means the gas price is high, or the network is congested.

The cheaper option: Polygon

On the same withdrawal screen, you likely see another choice: send to Polygon (or other layer 2 networks like Arbitrum or Optimism). Polygon is not Ethereum proper - it is a sidechain that settles transactions faster and cheaper. Its native token is MATIC (now POL), not ETH.

Select Polygon as the destination network. Your $100 withdrawal might cost pennies, not $12. Polygon fees work similarly: a base fee and priority fee, but in POL instead of ETH. Gas limits are comparable, but the base fee is orders of magnitude lower.

This is not a permanent escape hatch. You will hold tokens on Polygon, not Ethereum mainnet. To move them back to mainnet, you pay bridge fees (often higher). But for daily spending, gaming, or interacting with decentralized apps, Polygon is far more practical for small sums.

The "out of gas" trap

The real headache appears when you try to use your tokens directly. Say you send ETH to a wallet on Polygon. You connect that wallet to a decentralized exchange to swap tokens. You set a low gas limit - say 21,000 gas - because that worked before.

The swap fails. Your transaction is reverted. You still paid the fee. This is the "out of gas" error.

When you interact with a smart contract (swap, lend, mint), the gas limit must be high enough to cover the contract's computational steps. The wallet estimates this automatically, but you can override it. Underestimate, and the transaction runs out of gas mid-execution. The network processes what it can, collects the fee, and gives you nothing.

Never manually reduce the gas limit below the wallet's estimate for contract interactions. For simple ETH transfers, 21,000 gas is standard. For anything else, let the wallet set the limit.

Practical takeaways

• That $12 fee on a $100 withdrawal is high. A $1,000 withdrawal would still be $12 - gas scales with network conditions, not send amount.
• Polygon fees are usually under $0.01 per transaction. Choose it for small sums on Coinbase's withdrawal screen.
• Out-of-gas errors cost you the fee. Let the wallet manage gas limits for contract interactions.
• Gas prices fluctuate hourly. Check current fees on a site like Etherscan or PolygonScan before clicking "send."

Ethereum is expensive when its blocks are full. Layer 2 networks exist to solve that. Pick the right network for your use case. Your $100 goes further.

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