How Is the Cost of Executing a 51% Attack Calculated for a PoW Coin?

The cost is primarily calculated by estimating the hourly cost to rent or acquire the necessary mining hardware (hash rate) to achieve 51% of the network's total hash rate. This includes electricity costs, hardware depreciation, and the rental fee from mining marketplaces.

The cost is highly variable and directly proportional to the coin's total hash rate and the efficiency of the available mining hardware.