Ethereum gas.

Never paid a gas fee? Start here.

Every action on Ethereum costs a fee, and that fee is not a fixed price list — it moves with how busy the network is, second by second. The numbers above are that price right now. This section explains what they mean, how your final cost is actually calculated, and why the figure is so much smaller than the horror stories you may remember.

First, five words

Gas

The unit that measures computational work. A plain ETH transfer is always 21,000 gas; a token swap might be 150,000. It measures effort, not money.

Gwei

The unit the price of gas is quoted in. One gwei is one billionth of an ETH. It exists only for readability — "0.35 gwei" beats "0.00000000035 ETH".

Gas limit

The most gas you authorise a transaction to consume. Your wallet estimates it. Unused gas is refunded, so a generous limit costs nothing extra.

Base fee

The per-gas price the protocol sets for the current block. Everyone in that block pays it, and it is burned — destroyed, not paid to anyone.

Priority fee

The tip you add on top to be included sooner. This one goes to the validator. Base fee + priority fee is what you actually pay per unit of gas.

How your fee is actually calculated

There is only one formula, and it has two inputs — how much work you asked for, and the price of work right now:

Fee = gas used × (base fee + priority fee)

Say you send a plain ETH transfer while the base fee is 0.30 gwei and you tip 0.05 gwei:

1. Gas used: a simple transfer is fixed at 21,000 gas.
2. Price per gas: 0.30 + 0.05 = 0.35 gwei.
3. Total: 21,000 × 0.35 gwei = 7,350 gwei = 0.00000735 ETH.

The same arithmetic scales with complexity, which is why the type of transaction matters more than anything else you control:

• Send ETH — 21,000 gas. Fixed by the protocol, never varies.
• Send a token (USDC, USDT) — roughly 45,000-65,000 gas, because a contract has to update its own ledger.
• Swap on a DEX — roughly 120,000-200,000 gas, depending on how many pools the trade routes through.
• Mint an NFT or use a complex contract — 80,000 to several hundred thousand gas.

You cannot change how much gas an action needs. What you can change is when you do it, and how large a tip you attach.

Why gas is so much cheaper than you remember

If your mental image of Ethereum fees is a $50 swap, that image is several years out of date. Three changes stacked up:

1. EIP-1559 (August 2021) replaced the old blind first-price auction — where everyone guessed a bid and overpaid — with a protocol-set base fee that adjusts automatically each block. Predictable pricing removed most of the panic overbidding.
2. Dencun (March 2024) introduced blobs: a separate, much cheaper lane of data space reserved for layer-2 rollups. Before it, every L2 posting data to Ethereum was bidding against ordinary users for the same block space. Afterwards they were not.
3. The migration to L2s. Most everyday swapping, minting and bridging now happens on rollups. Mainnet increasingly settles those batches rather than processing each individual action.

The result: base fees that routinely sat at 20-100+ gwei during the 2021 peak now frequently sit below 1 gwei. That is a structural change in how Ethereum is used, not a quiet week — which is why the tracker above often shows fractions of a gwei.

It does still spike. A heavily hyped mint, a token launch, or sharp volatility that sets off liquidations and arbitrage bots can lift the base fee by an order of magnitude within a few blocks. The difference is that those are now events you can wait out, rather than the everyday baseline.

How to read the tiers above

The four tiers are not four different products. They are the same transaction with different tips attached, which buys you a different place in the queue:

• Slow — the smallest tip. Fine for anything with no deadline; may wait several blocks.
• Standard — the sensible default. Typically included within a block or two.
• Fast — a larger tip for time-sensitive actions, like a swap where the price is moving.
• Instant — maximum priority, for when missing the next block genuinely costs you more than the fee does.

Because the base fee is the same for everyone in a block, the gap between tiers is only ever the tip. When the network is quiet, that gap is often too small to be worth thinking about — paying for "instant" to save a few seconds may cost a fraction of a cent more. When the network is busy, the gap widens sharply and the choice starts to matter.

When gas is cheapest

Gas is pure supply and demand for block space, and demand follows human schedules. Two patterns hold up reliably:

• Time of day. The quiet UTC hours — roughly 00:00 to 06:00 — are usually cheaper than the overlap of European and US working hours.
• Day of week. Weekends are generally calmer than weekdays.

Neither is a rule you should trade on blindly; a big mint at 03:00 UTC will beat any calendar pattern. The reliable method is the boring one: if it is not urgent, look at the live number above, and if it is elevated, come back later.

The three things that go wrong

Out of gas

Your gas limit was lower than the transaction needed. It runs, exhausts the limit, and reverts — and the gas consumed is not refunded, because the work was performed. Let your wallet estimate the limit.

Stuck in the mempool

Your max fee was below the current base fee, so no block will take it. It sits until the base fee falls to meet it, or it is eventually dropped. Most wallets offer a speed-up that resubmits with a higher fee.

Failed but charged

A revert partway through — slippage exceeded, a condition not met — still consumed real computation, and you pay for it. Simulating the transaction in your wallet before confirming catches most of these.

The one line to remember: you pay gas used × (base fee + priority fee). The base fee is set by the network and burned; the tip is yours to choose and buys queue position. You cannot change what an action costs in gas — only when you do it.

⚠ The practical trap: gas is payable in ETH only. A wallet holding nothing but USDT or USDC on mainnet cannot move them, because there is no ETH to pay the fee with — and the fix requires bridging or sending ETH in first, which itself needs a fee paid from somewhere else. Always leave a small ETH balance in any wallet you actually transact from.