A gwei (gigawei) is one billionth of an ETH, or 10 to the power of 9 wei. Gas prices are quoted in gwei because the per-unit amounts are tiny. 1 ETH equals 1,000,000,000 gwei, so a 30 gwei gas price is 0.00000003 ETH per gas unit.

How is the total fee calculated?

Total fee in gwei is gas limit multiplied by gas price in gwei. Dividing by one billion converts to ETH, and multiplying by the ETH/USD price gives the dollar cost. A 21,000 gas transfer at 30 gwei costs 630,000 gwei, or 0.00063 ETH.

How does EIP-1559 change the gas price?

Under EIP-1559 the effective gas price you pay is the base fee plus your priority fee (tip), capped at your max fee. This tool adds the base fee and priority fee you enter to get the effective price, then applies it to the gas limit.

Why isn't the ETH price fetched automatically?

This tool is deliberately keyless and offline-friendly, so you enter the ETH price yourself from any source you trust. That keeps it fast, private, and free of API rate limits or wallet connections.

What gas limit should I use?

A simple ETH transfer is always 21,000 gas. ERC-20 token transfers typically use 45,000 to 65,000, a Uniswap swap around 120,000 to 200,000, and complex contract interactions can exceed 300,000. Your wallet estimates the limit before you sign.

Gas Fee gwei → USD Converter

Ethereum gas fees are quoted in gwei, a unit most people cannot intuitively convert to real money. This tool does the arithmetic: enter the gas limit, the gas price in gwei, and the current ETH/USD price, and it returns the transaction cost in gwei, ETH, and dollars. It supports EIP-1559’s split of base fee and priority fee, and it never needs an API key or a wallet connection.

How it works

The conversion chain is three multiplications and one unit shift:

1 ETH        = 1,000,000,000 gwei  (10^9)
effective gwei price = base fee + priority fee   (EIP-1559)
total fee (gwei) = gas limit × effective gwei price
total fee (ETH)  = total fee (gwei) / 1,000,000,000
total fee (USD)  = total fee (ETH) × ETH/USD price

Because gwei is one billionth of an ETH, the gas-limit-times-price product is divided by 10 to the power of 9 to land in ETH, and then scaled by the dollar price you supply.

Example and tips

A standard ETH transfer uses 21,000 gas. At a 30 gwei effective price the fee is 630,000 gwei, which is 0.00063 ETH; at an ETH price of 3,000 that is 1.89 USD. Contract-heavy transactions use far more gas, so the same gwei price can cost ten times as much on a Uniswap swap as on a plain transfer. When the network is busy the base fee rises automatically — set a priority fee just high enough to be included in the next block or two, and avoid overpaying during quiet periods.