Most blockchains use some form of fee market to calculate transaction fees. When a large number of people want to use the blockchain, the fees go up. Fees become more expensive as the demand for block space increases. The amount of fees cannot be predicted in advance and may change. Fees are heavily affected by network congestion, which is not ideal. Cardano does not have this commonly used mechanism. Transaction fees are fixed and predictable. We will explain to you how the amount of fees for transactions and Plutus scripts is calculated. We will also explain how Cardano behaves when it is overloaded and the planned improvement called tiered pricing.
Read the article: https://cexplorer.io/article/understanding-cardano-fees