Dosimetry is necessary to scale exposures across species to compare biological responses. The functionally equivalent exposure of a human is estimated from animal exposure by dosimetry. Induced electric fields and current densities were calculated for 50 Hz, 10 G, 20 G and 30 G magnetic fields exposures using ellipsoid models representing human standing and guinea pig on all four feet on the ground. E fields induced by 10 G, 20 G and 30 G fields of 50 Hz were calculated as 4.04 mV/m, 8.07 mV/m and 12.11 mV/m respectively for guinea pigs. For the human model these fields were found 12.5 mV/m, 25 mV/m and 37.7 mV/m. Induced current densities were calculated between 0.404 mA/M-2 and 1.211 mA/M-2 for guinea pig, between 1.25 mA/M-2 and 3.77 mA/M-2 for human by taking the conductivity 0.1 S/m. Average value of human : guinea pig ratios (Scaling Factor - SF) was calculated as 3.1. The functionally equivalent exposure of human was obtained from SF of 3.1 and found between 3.23 G and 9.68 G.