# Aptos Fees

An Aptos transaction must pay for both the computational cost of execution and the long-term cost of storing the objects that a transaction creates or mutates.

Each Aptos transaction is submitted with the following fields:

- **Max Gas Amount:** This provides a cap to the amount of gas units that will be used by transaction. The maximum gas amount for an Aptos transaction is defined in Octa units (**1 APT = 100,000,000 Octa**).
- **Gas Price:** The reference gas price is the real-time cost of executing a transaction in Octa units.


The transaction fee charged for the transaction will be at most: `gas_price * max_gas_amount`.

Aptos transaction contain [fee statements](https://aptos.dev/en/network/blockchain/gas-txn-fee#the-fee-statement), describing the breakdown of gas used in the transactions - these are available via Fordefi APIs both for on-chain transaction and when predicting a transaction.

Fordefi provides the option to define each of these fields through the API endpoint. The UI currently does not support changing these values.