A transactional memory system dynamically predicts the resource requirements of hardware transactions. A processor of the transactional memory system predicts resource requirements of a first hardware transaction to be executed based on a resource hint, a type of hardware transaction that is associated with a given hardware transaction, and a previous execution of a prior hardware transaction that is associated with the type of hardware transaction. The processor allocates resources for the given hardware transaction based on the predicted resource requirements. The processor initiates execution of the first hardware transaction using at least a portion of the allocated resources.