Crypto Gas Fee Calculator — Estimate ETH Transaction Cost
Estimate Ethereum gas fees in ETH and USD. Enter gas units, gas price in gwei, and ETH price — with presets for common transaction types. Free crypto gas calculator.
Every Ethereum transaction pays a gas fee to compensate validators for executing your transfer, swap, or smart-contract call. Gas fees spike when the network is busy and fall when it is quiet, so knowing the cost before you confirm can save you from an expensive surprise.
This gas fee calculator multiplies gas units by the gas price (in gwei) and the ETH/USD price you provide. No live price feed is required — paste the current ETH price from your exchange or wallet. Use the presets for common transaction types, then adjust gas limit and gwei to match what your wallet quotes.
How Ethereum gas fees are calculated
Gas fee (ETH) = gas units × gas price (gwei) × 10⁻⁹. Multiply that ETH amount by the ETH/USD price to get the fee in dollars. Gas units (also called gas limit) measure how much computation a transaction needs. A simple ETH transfer uses 21,000 gas. A token approval or Uniswap swap can use 50,000–250,000+ depending on the route and contract complexity.
Gas price is denominated in gwei (1 gwei = 0.000000001 ETH). During quiet periods you might see 5–15 gwei; during NFT mints or market volatility it can jump above 100 gwei. EIP-1559 split fees into a base fee (burned) plus an optional priority tip, but for estimation the wallet’s “max fee” in gwei × gas units is what you ultimately pay at most.
Layer-2 networks (Arbitrum, Optimism, Base) use the same gas model but with much lower effective prices. You can still use this calculator for L2s by entering that network’s gas units and gwei from your wallet.
Common transaction gas ranges
ETH transfer: 21,000 gas. ERC-20 token transfer: typically 45,000–65,000 gas. Token approval (approve): ~45,000 gas. Uniswap-style swap: often 100,000–250,000 gas depending on hops. NFT mint: highly variable — 80,000 to several hundred thousand gas.
Always check your wallet’s estimate before confirming. Presets here are planning defaults, not guarantees. If a dapp shows a much higher gas limit, trust the dapp — underestimating gas causes the transaction to fail while still consuming the fee for work performed.
Tips to pay less gas
Send transactions during off-peak hours (weekends / late UTC nights often quieter). Use a gas tracker to wait for lower gwei. Prefer Layer-2 networks for frequent small transfers and swaps. Avoid unnecessary token approvals, and revoke unused allowances periodically.
Setting an extremely low gwei can leave a transaction pending for hours or days. If speed matters (bridging, liquidations, NFT drops), pay the wallet’s recommended fee rather than optimizing for the absolute minimum.
How to use this calculator
- Choose a transaction preset (ETH transfer, token transfer, approval, swap, or custom) to fill a typical gas-unit value.
- Enter the gas price in gwei from your wallet or a gas tracker.
- Enter the current ETH price in USD (from your exchange — this tool does not fetch live prices).
- Optionally override gas units for custom contracts.
- Click Calculate to see the fee in ETH and USD.
Worked example: Uniswap swap at 25 gwei with ETH at $3,000
Assume a swap uses 180,000 gas at 25 gwei. Fee in ETH = 180,000 × 25 × 10⁻⁹ = 0.0045 ETH.
At $3,000 per ETH, the USD fee is 0.0045 × 3,000 = $13.50.
If gas jumps to 80 gwei on a busy afternoon, the same swap costs 0.0144 ETH ≈ $43.20 — over 3× more. Waiting for quieter gwei can materialize real savings.
Frequently asked questions
What is gwei?
Gwei is a denomination of ETH equal to 0.000000001 ETH (10⁻⁹). Gas prices are quoted in gwei so you do not have to work with many decimal places of ETH.
Why did my transaction fail but still cost gas?
Ethereum charges for computation performed. If your transaction runs out of gas or reverts after work was done, you still pay for that work. Failed swaps and under-priced gas limits are common causes.
Does this calculator use a live ETH price?
No. Enter the ETH/USD price yourself from your exchange or wallet. That keeps the tool fast, private, and free of third-party API dependencies.
Can I use this for Bitcoin fees?
Bitcoin fees work differently (sat/vB based on transaction size, not EVM gas). This calculator is designed for Ethereum-style gas markets and compatible EVM chains / L2s.