What Are Gas Fees? Understanding Gas Price, Gas Limit, and How to Manually Set Gas in MetaMask

·

Gas fees are transaction fees paid to miners for processing and validating transactions on the blockchain. Think of them as tolls for using the blockchain highway—without paying enough, your transaction won't be added to the chain.

Key Takeaways:


Why Do We Pay Gas Fees?

Originally specific to Ethereum, the term "Gas Fee" now broadly refers to miner/validator fees across blockchains. Blockchains rely on miners to:

Miners earn rewards through:

  1. Transaction fees (Gas).
  2. Block rewards (mining).

Higher Gas fees = Priority processing by miners.


Gas Fee Structure Explained

Gas Fee = Gas Price (Gwei) × Gas Limit

| Component | Role | Analogy |
|-----------------|---------------------------------------|-----------------------|
| Gas Price | Price per unit of Gas (in Gwei) | Cost per liter of fuel|
| Gas Limit | Max units of Gas a transaction uses | Fuel tank capacity |

Example: An NFT buyer paid 22 ETH in Gas for a 1 ETH NFT to prioritize their transaction.


How to Manually Adjust Gas in MetaMask

  1. Enable Advanced Gas Controls:

    • Go to Settings → Advanced → Toggle "Advanced Gas Controls".
  2. Edit Gas Fees During Transactions:

    • Click Edit on the transaction preview.
    • Adjust Gas Limit (units needed) and Gas Price (Gwei).

Note: Gas fees are paid in the chain’s native currency (e.g., ETH for Ethereum, BNB for BSC).


Accelerating Stuck Transactions

  1. Speed Up:

    • In MetaMask, find the pending transaction → Click Speed Up → Increase Gas Price by 10%.
  2. Custom Nonce Override:

    • Enable Custom Nonce in Advanced Settings.
    • Locate the stuck transaction’s nonce (in transaction details).
    • Initiate a new transaction with the same nonce and higher Gas.

👉 Learn advanced Ethereum transaction strategies

Warning: Incorrect nonce values may lead to rejected transactions.


Real-Time Gas Fee Trackers

  1. Etherscan Gas Tracker:

    • Shows Slow/Avg/Fast Gas Prices on Ethereum.
  2. Blocknative Gas Estimator:

    • Supports Ethereum and Polygon.

FAQ

Q: What happens if my Gas Limit is too low?

A: The transaction fails, but spent Gas isn’t refunded.

Q: Why would I pay a high Gas Price?

A: To prioritize your transaction during network congestion.

Q: Can I cancel a stuck transaction?

A: Yes—override it with a new transaction using the same nonce.

👉 Explore MetaMask’s full features

Pro Tip: Always check real-time Gas fees before sending transactions.