An Electromagnetic Pulse (EMP) is an intense burst of electromagnetic energy caused by a sudden, rapid acceleration of electrons. EMPs are a known issue for facilities delivering picosecond (ps) long laser pulses and can last for orders of magnitude longer than the original laser pulse length. Issues include interference with diagnostic devices, actuators and even damage on electrical components. Recent advances of Petawatt (PW) lasers enable ultrashort femtosecond (fs) time regime pulses and the establishment of large scale laser facilities imposes the demand for reliable operation of its beamlines. However up to now, no systematic study is available investigating EMPs at multi-Joule femtosecond class lasers. In this paper, scaling laws are presented connecting the energy of the EMPs with various laser parameters. Furthermore, we simulated the generated EMP emitted by the target holder. This study will enable more efficient target design, with respect to EMP handling, in laser facilities performing ultra-high intensity experiments.