Gwei

What is gwei?

Gwei is a denomination of ether (ETH), the native cryptocurrency of the Ethereum blockchain. It is commonly used to quote transaction fees (gas prices) because gas costs are typically very small fractions of an ETH.

• 1 gwei = 0.000000001 ETH (10^-9 ETH)
• 1 gwei = 1,000,000,000 wei (10^9 wei)

Wei is the smallest unit of ether; 1 ETH = 10^18 wei.

Why gwei matters

Ethereum transaction fees (gas) compensate validators for the computation and storage required to process transactions and run smart contracts. Gas prices are quoted in gwei to make these small amounts easier to read and compare. When you set a gas price, you specify how many gwei you are willing to pay per unit of gas; the total fee equals gas price × gas used.

Example:
– Gas price = 5 gwei
– Gas limit for a simple transfer = 21,000 gas
– Fee = 5 × 21,000 = 105,000 gwei = 0.000105 ETH

Ether denominations (common units)

Ethereum uses multiple denominations to express values more conveniently. Common units and their relationships:

• wei — 1 wei = 10^-18 ETH (smallest unit)
• kwei (babbage) — 1 kwei = 10^3 wei = 10^-15 ETH
• mwei (lovelace) — 1 mwei = 10^6 wei = 10^-12 ETH
• gwei (shannon) — 1 gwei = 10^9 wei = 10^-9 ETH
• szabo (twei) — 1 szabo = 10^12 wei = 10^-6 ETH
• finney (pwei) — 1 finney = 10^15 wei = 10^-3 ETH
• ether (buterin) — 1 ether = 10^18 wei = 1 ETH

These informal nicknames honor historical figures in computing and cryptography (for example, “shannon” for Claude Shannon).

Quick conversions

• 1 ETH = 1,000,000,000 gwei
• 1 gwei = 0.000000001 ETH
• To convert gwei → ETH: multiply gwei by 10^-9
• To convert ETH → gwei: multiply ETH by 10^9

Key takeaways

• Gwei is a convenient unit for expressing Ethereum gas prices and small ETH amounts.
• 1 gwei = 10^-9 ETH = 10^9 wei.
• Transaction fee (ETH) = gas price (gwei) × gas used × 10^-9.
• Using gwei avoids unwieldy decimal strings when quoting typical gas prices.

Conclusion

Gwei is the most commonly used subunit of ether for everyday Ethereum activity because it simplifies the expression of gas prices and other small ETH values. Understanding gwei and the denomination scale helps when setting gas prices, estimating fees, and reading transaction costs.