What Is the Minimum Hash Rate Required for a Successful 51% Attack on Bitcoin?

There is no fixed minimum hash rate, as the required power is always 51% of the current total network hash rate. This total hash rate is constantly fluctuating based on the number of active miners.

For a large network like Bitcoin, this requirement translates to a prohibitive amount of computational power and an astronomical, ongoing energy cost. The economic barrier to acquiring 51% of the total hash rate is what makes a sustained attack practically impossible.