Gas Fee Calculator
Gas units times gwei times ETH price, with presets for the transactions people actually send. The DEX swap line is usually the eye-opener.
Results (live)
Estimates only, not financial advice. All math runs in your browser; nothing you type leaves this page.
How it works
fee ETH = gas units × gwei ÷ 1,000,000,000
fee USD = fee ETH × ETH price
Worked example
A swap (~150,000 gas) at 20 gwei with ETH at $3,200 costs 0.003 ETH, $9.60. The same swap in a 200-gwei spike costs $96.
FAQ
Why did the same swap cost 10× more yesterday?
Gas price floats with demand. Gas units for the action barely change; gwei is the whole difference, and it spikes during mints and crashes.
How do I pay less?
Transact when gwei is low (weekends, off-US hours), or use an L2 where the same swap often costs cents.
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Estimates only, not financial, tax or investment advice. Verify numbers against your exchange or a professional before acting. Live prices, where used, come from the public CoinGecko API.