Gwei to ETH converter with exact wei arithmetic
Ethereum prices gas in gwei, wallets show balances in ETH, and smart contracts, block explorers and RPC responses speak in wei. This gwei to ETH converter moves any amount between those three units and the rarer ones in between — kwei, mwei, szabo and finney — using exact integer maths, so 123456789.123456789 gwei really does become 123,456,789,123,456,789 wei rather than a rounded floating-point approximation.
Below the table is a small gas fee estimator: multiply the gas units a transaction uses by the gas price in gwei and you get the fee in ETH, gwei and wei. If you type in the current ETH price, it also shows the fee in your currency. Nothing is fetched from the network; the rate is whatever you enter.
Everything runs in your browser. The page is informational only and is not investment, tax or financial advice.
How to use the Gwei to ETH Converter
- Type an Amount and choose its Unit — for example 25 gwei or 0.05 ether.
- Read the headline value in ETH and the full table of every unit. Use the small copy buttons to grab a single value, or Copy conversion table for all of them.
- For a fee estimate, enter the Gas units (21,000 for a simple transfer) and the Gas price your wallet shows in gwei.
- Optionally enter the current ETH price to see the fee in your own currency.
- If the amount has more decimal places than the unit allows (say 0.0000000001 gwei, which is a tenth of a wei), the converter tells you instead of silently rounding.
Gwei to ETH Converter features
Exact to the wei
Amounts are parsed into BigInt integers, so values with up to 18 decimal places are converted without floating-point drift.
All seven named units
wei, kwei (babbage), mwei (lovelace), gwei (shannon), szabo, finney and ether are shown side by side.
Gas fee estimator
Gas units × gas price in gwei gives the fee in ETH, gwei and wei — the same formula your wallet uses for the “max fee”.
Fiat at your rate
Type the ETH price you see on your exchange and the fee is shown in that currency. No price feed, no tracking.
Copy-ready output
Plain decimal strings, suitable for pasting into a script, a spreadsheet or an RPC call.
Ethereum unit table
Ether is divisible into 1018 wei. The intermediate names honour cryptography pioneers; only wei, gwei and ether are used day to day.
| Unit | Wei | Also called | Typical use |
|---|---|---|---|
| wei | 1 | — | Smallest unit; balances in contracts and RPC responses |
| kwei | 103 | babbage | Rare |
| mwei | 106 | lovelace | Rare |
| gwei | 109 | shannon | Gas prices |
| szabo | 1012 | microether | Rare |
| finney | 1015 | milliether | Rare |
| ether | 1018 | ETH | Balances, prices |
How a gas fee is calculated
Since EIP-1559 (August 2021) every transaction pays gas used × (base fee + priority fee), where the base fee is set by the protocol per block and burned, and the priority fee is the tip you offer to the block proposer. Your wallet shows a “max fee per gas” that caps both together; the estimator here treats whatever you type as that per-gas price.
Worked example: a plain ETH transfer uses exactly 21,000 gas. At 1 gwei per gas the fee is 21,000 × 1 gwei = 21,000 gwei = 0.000021 ETH. At 25.5 gwei and 65,000 gas (a typical ERC-20 transfer) the fee is 1,657,500 gwei = 0.0016575 ETH. Multiply by the ETH price to get the cost in dollars, rupees or pounds.
- Gas units measure computational work and do not change with price; gas price in gwei moves with network demand.
- Unused gas is refunded, so the fee charged is based on gas actually used, up to your gas limit.
- Layer-2 networks such as Arbitrum, Optimism and Base use the same units but their gas prices are usually fractions of a gwei — the converter handles those decimals exactly.
- For the base fee and tip split, presets for token sends and swaps, and an L2 comparison, use the Ethereum gas fee calculator.
Why integer maths matters
JavaScript’s ordinary numbers hold about 15–16 significant digits, but an ETH balance expressed in wei can have 25 or more. A naive converter that does amount * 1e18 can silently change the last digits — harmless when you are eyeballing a price, costly when the value goes into a transaction. This page keeps every amount as an arbitrary-precision integer in wei and only formats it for display, which is the same approach libraries such as ethers.js and viem take. For tokens with other decimal counts (USDC with 6, WBTC with 8) use the token unit converter; for Bitcoin, the satoshi to BTC converter.
Gwei to ETH Converter FAQ
How many gwei are in 1 ETH?
One ETH is 1,000,000,000 gwei (109), and one gwei is 1,000,000,000 wei. So 1 ETH is 1018 wei.
What does gwei stand for?
“Giga-wei”: a billion wei. It is also nicknamed “shannon” after Claude Shannon. Gas prices are quoted in gwei because a single wei is far too small to be practical.
How do I convert gwei to ETH by hand?
Divide by one billion. 30 gwei = 30 ÷ 1,000,000,000 = 0.00000003 ETH. To go the other way, multiply ETH by 1,000,000,000.
Why is my gas fee different from this estimate?
The estimator multiplies the gas units and gas price you typed. Real transactions pay the base fee of the block they land in plus your tip, and complex contract calls can use more or less gas than expected. Treat the result as a planning figure, not a quote.
Does this gwei to ETH converter fetch the live ETH price?
No. It makes no network requests at all. If you want a fiat figure, type the current price in the ETH price box; the conversion then uses exactly that number.
Is this financial advice?
No. The page is a unit converter and arithmetic helper. It does not recommend buying, selling or holding anything.