Blockchain transaction fees vary from negligible to substantial within hours. The variation is not arbitrary pricing; it is the result of bidding for a fixed and scarce resource.
Block space is capped by design
Each block accepts a limited amount of transaction data, and blocks are produced at roughly regular intervals set by the protocol.
Throughput is therefore bounded regardless of how many people want to transact, which makes block space a genuinely scarce commodity.
The cap exists so that every participating node can validate and store the chain, since raising it would concentrate participation among better-resourced operators.
Fees are bids in a continuous auction
Pending transactions sit in a queue, and block producers select from it. Since producers keep the fees, they prioritise the transactions paying most.
A user setting a low fee may wait through many blocks or never confirm at all if demand does not subside.
Wallets estimate a fee likely to confirm within a target time by observing the queue, which is why the suggested figure changes minute to minute.
Transaction size is measured in computation, not value
The fee depends on how much space or computational work the transaction consumes, not on the amount being transferred.
Moving a large sum in a simple transfer can cost less than executing a complex contract interaction that shifts almost nothing.
This is why network congestion is driven by activity types rather than by transaction values, and why particular applications can raise costs for everyone.
Base fee mechanisms smooth the bidding
Some networks set an algorithmic base fee that adjusts according to how full recent blocks were, with users adding a tip to prioritise their transaction.
The base fee rises when blocks are consistently full and falls when they are not, which makes fee estimation more predictable than pure open bidding.
On several networks the base portion is destroyed rather than paid to the producer, which removes the incentive to manufacture artificial congestion.
Layered networks move activity off the base chain
Secondary networks execute transactions elsewhere and periodically post compressed proofs or data back to the main chain.
Because many transactions share the cost of one settlement, the per-transaction fee falls substantially while security still derives from the base layer.
The trade-off is added complexity, dependence on the operators of the secondary network, and delays or costs when moving funds between layers.