Why blockchain fees change, and how to pay less

What a fee actually buys

A blockchain adds transactions in batches called blocks, and every block has a size limit. Bitcoin produces a block about every 10 minutes, capped at 4 million weight units. Ethereum produces one every 12 seconds, each with a gas limit. Whatever the unit, space is scarce, and your fee is a bid for a share of it.

Fees also deter spam: Bitcoin.org says they protect "against users sending transactions to overload the network". Depending on the network, the fee goes to miners or validators, is burned (destroyed), or is split between them.

For everyday users, the key point is that the fee depends on the room or computation a transaction takes, not the amount: sending 0.01 BTC can cost as much as sending 10 BTC.

Bitcoin: paying by size, in sat/vB

On Bitcoin, the fee is size times rate. Size is measured in virtual bytes (vB), a unit defined by the SegWit upgrade (BIP 141) that counts signature data at a discount. The rate is quoted in satoshis per virtual byte, or sat/vB; a satoshi is one hundred-millionth of a bitcoin.

A simple payment from a modern SegWit address, spending one input and creating two outputs (the payment and your change), is about 140 vB. At 2 sat/vB that costs about 280 satoshis; at 50 sat/vB, about 7,000. What makes a transaction bigger is mainly the number of inputs (the earlier payments it spends), not the amount sent.

Unconfirmed transactions wait in the mempool, each node's pool of transactions eligible for the next block. Miners generally fill blocks with the highest fee rates first, so when the mempool is crowded, you are bidding against everyone else. On 20 April 2024, the day of the fourth halving, the median rate in block 840,000 was about 200 sat/vB. On 29 September 2026, mempool.space's estimate for the next block was 1 sat/vB.

Fees are also part of miners' pay; see Bitcoin's 21 million cap and the halving.

Ethereum and layer-2 rollups: gas, base fee and tip

Ethereum measures work in gas. A plain ETH transfer uses 21,000 gas; token transfers and swaps use more. The fee is the gas used multiplied by two prices added together: the base fee and the priority fee, or tip. Prices are quoted in gwei, a billionth of an ETH.

The base fee is set by the protocol, not by you, and it is burned. Under EIP-1559, each block has a gas target at half its limit. If a block uses more than the target, the next base fee rises, by up to 12.5% after a completely full block; if it uses less, the base fee falls. The tip goes to the validator who includes your transaction, and it matters mostly when many people compete at once.

Eight full blocks in a row take about 96 seconds and leave the base fee more than two and a half times higher. So wallets set a maximum fee with room to spare; you pay only the base fee plus tip, and the rest is refunded.

Layer-2 rollups

A layer 2 is a separate network that extends Ethereum and inherits its security. Rollups, a type of layer 2, bundle hundreds of transactions into a single transaction on Ethereum, so its cost is shared among everyone in the batch. On OP Mainnet, for example, a fee's main parts are an execution fee, priced like Ethereum gas, and a charge for posting the data to Ethereum.

Since Ethereum's Dencun upgrade on 13 March 2024, rollups can post that data as blobs, temporary data kept for about 18 days with its own fee market. Ethereum.org says this "results in significantly lower transaction fees for users of layer 2 rollups." Rollup fees still rise when the rollup or blob space gets busy.

TRON, Solana and Stellar

TRON: bandwidth and energy

TRON charges in two resources. Bandwidth covers a transaction's size in bytes, and energy covers the computation a smart contract performs. A plain TRX transfer needs only bandwidth. A token transfer, such as USDT on TRON, runs a smart contract, so it needs energy too.

Every account gets 600 free bandwidth points over a rolling 24 hours. Beyond that, you can stake TRX for resources; otherwise the network burns TRX from your balance: as of September 2026, 0.001 TRX per byte of bandwidth and 0.0001 TRX per unit of energy. These rates are network parameters that governance proposals can change.

Costs still move, though. Under TRON's dynamic energy model, heavily used contracts can cost up to 4.4 times their base energy, recalculated every six hours. Sending to an address that has never been used on TRON also costs extra, because the transfer activates the account.

Solana: base fee and priority fees

Every Solana transaction pays a base fee of 5,000 lamports per signature, or 0.000005 SOL (a lamport is a billionth of a SOL). Half is burned and half goes to the validator. You can add a priority fee, priced per compute unit requested, which makes it more likely that the validator producing the current block schedules your transaction ahead of others. All of it goes to that validator.

Sending a token to someone who has never held it can cost more, because a token account must be created for them, holding a minimum balance of about 0.002 SOL.

Stellar: a tiny base fee, with surge pricing

Stellar charges per operation, and one transaction can contain several. The network minimum is 100 stroops per operation, or 0.00001 XLM; a stroop is a ten-millionth of a lumen, Stellar's coin. You set the most you're willing to pay, but normally you pay only the minimum.

Stellar's blocks are called ledgers. When more ordinary operations are submitted than fit in one ledger (1,000 on Mainnet as of July 2026), surge pricing starts: transactions are ranked by fee, and everyone included pays the lowest fee among them. Smart-contract transactions add a resource fee.

Why congestion moves prices

All of these systems react to the same pressure: more transactions than space. In auction-style markets, such as Bitcoin, Solana's priority fees and Stellar's surge pricing, senders outbid one another. On Ethereum, the protocol raises the base fee block after block until demand cools. TRON fixes unit prices through governance, so heavy use shows up as higher energy costs for popular contracts.

Rushes can arrive suddenly and fade once demand eases, which is why a fee quoted a minute ago may already be out of date.

Comparing the networks

Protocol figures are as of 29 September 2026. What a transfer costs in money depends on demand and coin prices, so the last column is relative only.

How to pay less

Choose the network

Many coins and stablecoins, such as USDT and USDC, exist on several networks, and moving the same token can cost very different amounts on each. If the recipient accepts it, a cheaper network can save a lot.

Time your transfer

If it isn't urgent, wait for a quieter moment. Bitcoin and Ethereum fees react to demand within minutes, and your wallet's estimate shows the current level. On Bitcoin, a slower confirmation target usually means a lower rate.

Send fewer, larger transfers

Every transaction pays its own fee, whatever the amount, so ten small transfers cost about ten times as much as one. On Bitcoin, many small incoming payments also mean many inputs, which make later transactions bigger and more expensive.

Check the fee before you confirm

Look at the network fee, the total leaving your balance and what the recipient will get. A good wallet shows all three before you confirm; in nowcoin, the Withdraw screen does, and asks you to confirm again if the fee changes.