What is gwei? Gwei to ETH and Ethereum gas prices explained
Gwei is a unit of ether (ETH), Ethereum’s native cryptocurrency: one gwei equals 0.000000001 ETH, or one billionth of an ether. It is the unit used to quote Ethereum gas prices, so when a wallet says “gas: 10 gwei”, it means you pay 10 billionths of an ETH for each unit of gas your transaction uses. You will mostly see gwei when you send crypto from your own wallet, not when you trade on an exchange.
Gwei meaning: how much is one gwei?
One gwei is one billionth of an ether. The name is short for gigawei: one billion wei, where wei is the smallest unit of ether. Ether has a fixed number of decimal places, 18, so one ether is made up of 1,000,000,000,000,000,000 wei.
| Unit | In wei | In ETH |
|---|---|---|
| Wei | 1 | 0.000000000000000001 ETH |
| Gwei | 1,000,000,000 | 0.000000001 ETH |
| Ether (ETH) | 1,000,000,000,000,000,000 | 1 ETH |
To convert gwei to ETH, divide by one billion. For example, 210,000 gwei is 0.00021 ETH. To go from ETH to gwei, multiply by one billion.
Where the names come from
The smallest unit, wei, is named after Wei Dai, a computer scientist who described an early digital currency idea called b-money in 1998. Other Ethereum denominations honour computing pioneers too: gwei is also called “shannon”, after Claude Shannon, the founder of information theory, and the kwei is called “babbage”, after Charles Babbage. In practice almost everyone uses just three units: wei, gwei and ether.
Watch out for one source of confusion: at least one token trades under the ticker GWEI. That token has nothing to do with the gwei unit.
Why Ethereum uses gwei for gas fees
Ethereum uses gwei because gas prices in ETH would be awkward tiny decimals. “10 gwei” is easier to read than “0.00000001 ETH”, and it makes price differences easy to compare.
Gwei is not the fee itself. It is the price per unit of gas. Your total fee is that price multiplied by the number of gas units your transaction uses, as our page on gas fees explains in detail.
How Ethereum gas fees work
Ethereum gas fees pay for the computational effort required to process a transaction. Every operation on the Ethereum network uses gas, like fuel for an engine, and you pay for that gas in ETH.
- A simple ETH transfer always uses 21,000 gas units.
- Interacting with smart contracts, such as swapping tokens or using decentralised applications, uses more, because there are more operations to run.
- If a transaction fails, you still pay for the gas used until it failed.
EIP-1559: how Ethereum gas prices are set
Since the London upgrade of August 2021, known as EIP-1559, the gas price is the sum of two parts, and you set a cap on the total.
Base fee
The base fee is set by the protocol itself, based on how full recent blocks were. When network demand is high and blocks are full, the base fee rises from one block to the next; when blocks are emptier, it falls. The base fee is burned, so it goes to no one.
Priority fee
The priority fee is a tip to the validator who includes your transaction. A higher tip makes it more likely your transaction goes into the next block, which matters when the network is busy and you care about transaction speed.
Max fee
The max fee is the most you’re willing to pay per unit of gas. If the base fee plus your tip turns out lower than your max fee, the difference is refunded. Most wallets fill in all three values for you, with “slow”, “normal” and “fast” options.
Gas price under EIP-1559
Gas price paid = base fee + priority fee (never more than your max fee)
What is the gas limit?
The gas limit is the maximum amount of gas you allow a transaction to use. For a simple ETH transfer it is 21,000. Smart contracts may need a higher gas limit, and most wallets estimate it for you. A higher gas limit doesn’t cost more by itself, because you only pay for the gas actually used; a limit that’s too low makes the transaction fail.
How to calculate the gas fee in gwei
The total fee equals gas units used multiplied by the gas price in gwei. Here’s a simple ETH transfer with a base fee of 8 gwei and a tip of 2 gwei:
- Add up the gas price. 8 gwei base fee + 2 gwei priority fee = 10 gwei per unit of gas.
- Multiply by the gas used. 21,000 units × 10 gwei = 210,000 gwei.
- Convert to ETH. 210,000 gwei ÷ 1,000,000,000 = 0.00021 ETH.
- Convert to euros. If ETH were worth €3,000, the fee would be 0.00021 × €3,000 = €0.63.
Run the same transfer at 50 gwei and the cost is five times higher: 0.00105 ETH, or €3.15 at that ETH price.
Why Ethereum gas prices rise
Ethereum gas prices rise because of network congestion. Block space is limited, so when many users want to transact at once, the base fee climbs automatically and people add bigger tips to get ahead in the queue.
Higher gas prices hit complex transactions hardest. A token swap uses several times more gas than a simple ETH transfer, so at a high gwei price the gap in euros becomes large.
Gwei and gas fees vs exchange fees
Gwei-based gas fees are network fees paid to Ethereum; exchange fees are charges set by a company. On a centralised exchange you mostly see exchange fees: a trading fee when you buy or sell, and a fixed withdrawal fee when you move ETH to your own wallet. The exchange pays the actual gas cost behind the scenes. Check the provider’s current fee page before you withdraw, and see our guide to trading fees for the full picture.
How to reduce Ethereum gas fees
You can lower the gwei price you pay with a few habits:
- Send when it’s quiet. Gas prices tend to be lower when fewer people are active.
- Review the estimate. Check the gas price in gwei and the total fee in euros before you confirm.
- Use a layer 2. Layer 2 networks usually cost a fraction of a transaction on Ethereum’s main chain, but check that the receiving side supports the same network.
- Don’t cut the gas limit. A limit that’s too low makes the transaction fail, and you still pay for the gas used.
Where to check Ethereum gas prices
You can check the current gas price on a reputable gas tracker or block explorer, which shows the base fee and suggested tips in gwei. Your wallet’s estimate is based on the same data, but it changes from block to block, so look at it just before you confirm.
What gwei means for European crypto users
For most European investors, gwei matters only when you use a self-custody wallet. Exchanges often show network fees in euros or as a flat withdrawal fee instead. Whichever way a fee is shown, use a provider with a MiCA licence, which must publish its fees clearly. Remember that ETH itself is volatile: crypto-assets can lose all their value.
Related terms
Questions people ask
How many ETH is 1 gwei?
One gwei is 0.000000001 ETH, or one billionth of an ether. Put the other way round, one ether equals 1,000,000,000 gwei.
How much is 1 gwei in US dollars or euros?
Divide the ETH price by one billion. If ETH were worth €3,000, one gwei would be worth €0.000003. Because the ETH price moves all the time, so does the value of a gwei.
What does gwei mean?
Gwei is short for gigawei: one billion wei, where wei is the smallest unit of ether. It is the unit wallets and gas trackers use to show Ethereum gas prices.
What is ETH gwei?
ETH gwei is just another way of saying gwei: a small denomination of ETH, like cents are to the euro but far smaller. Gas prices such as 10 gwei mean 10 billionths of an ETH per unit of gas.
Why do I have to pay a gas fee?
Every Ethereum transaction uses computing power from the network. The gas fee pays validators to process and secure your transaction, and stops people from flooding the network with spam.