Cardano Smart Contract Fees: How Plutus Execution Costs Work
SMART CONTRACT COSTS
Understanding ADA Fees for Smart Contract Interactions
Why do smart contract transactions cost more on Cardano?
Smart contract transactions include a base network fee (a × size + b) plus an execution budget covering the CPU steps and memory units consumed by the Plutus script. The execution budget is priced using two additional protocol parameters: priceExSteps (cost per CPU step) and priceExMem (cost per memory unit). Together these can add 0.1–0.6 ADA on top of the base fee.
What is the EUTXO model and how does it affect fees?
Cardano uses the Extended Unspent Transaction Output (EUTXO) model. Unlike Ethereum's account-based model, EUTXO validates all script inputs before the transaction is submitted. This means failures are caught off-chain and you never lose your fee to a failed transaction—a significant advantage for DeFi users.
How much does a typical DeFi swap cost on Cardano?
A typical DEX swap on Cardano (e.g., on Minswap or SundaeSwap) costs between 0.3 ADA and 0.6 ADA in network fees, depending on script complexity and transaction size. This is separate from the DEX's own protocol fee (usually 0.3–1% of the swap value). Total cost remains substantially lower than Ethereum mainnet swaps during high-demand periods.
What are CPU steps and memory units in Cardano fees?
CPU steps measure the computational work required to execute a Plutus script. Memory units measure the maximum memory the script can allocate during execution. Both are capped per transaction and per block, ensuring scripts cannot monopolize network resources. Costs are determined by multiplying usage by the respective price parameters set in the protocol.
Can smart contract execution fail on Cardano?
Thanks to the EUTXO model, Cardano validates transactions deterministically off-chain before submission. If the transaction would fail, your wallet prevents submission, and you pay no fee. This contrasts with Ethereum, where a failed transaction still consumes gas. Cardano's approach protects users from wasted fees during complex DeFi interactions.
How do NFT minting fees compare to transfer fees on Cardano?
Minting a native token or NFT on Cardano adds a minting policy script to the transaction. Simple minting policies (e.g., time-locked mints) have minimal execution costs, producing total fees of 0.2–0.35 ADA. Complex minting policies with Plutus validation can run 0.4–0.8 ADA. There is also a minimum ADA deposit (~1.5–2 ADA) required to carry tokens in a UTXO, which is returned when the token is burned.