How fees are generated from transactions in crypto

Transaction fees in cryptocurrency come from the need to pay people who help process and secure transactions on the blockchain. When you send crypto, like Bitcoin or Ethereum, your transaction sits in a waiting area called the mempool until someone adds it to the blockchain.

In Bitcoin, miners do this work. They collect many transactions, solve a hard math puzzle, and create a new block. To encourage miners to pick your transaction quickly, especially when the network is busy, you attach a fee. The fee is calculated mainly by the size of your transaction in bytes and how much you’re willing to pay per byte in satoshis. Miners choose transactions with the highest fees first because they earn more. Once your transaction is in a block, the miner keeps all the fees from every transaction in that block as their reward, on top of the fixed new Bitcoin they get.

Ethereum works differently but follows the same idea. Every action, like sending ETH or using a smart contract, uses “gas.” Gas measures computational effort. You set a gas price in gwei and pay for the gas your transaction actually uses. When the network is crowded, people bid higher gas prices to get included faster. Validators who secure the chain collect these fees. Since 2021, a big portion of Ethereum fees gets burned, meaning it disappears forever, which reduces the total supply of ETH.

Other blockchains do similar things. Some burn part of the fee to fight spam, some share fees with people who stake coins, and some keep fees very low by processing many transactions off-chain. In every case, fees exist because users compete for limited space on the blockchain, and the people doing the work get paid for it.