This research has purposed to derive efficiency equation of the prototype of pico wind turbine produces the electricity (PPWTPE). By using a ventilating fan of 12 cm diameter as a blower, at rotating speed of 2,880 rpm. Blower blew the wind to PPWTPE of alternator. The wind turbine of alternator modified from magnet motor of central processing unit fan of computer. Magnet motor composes of the cylindrical magnet 30 mm diameters, magnetic field intensity of 70 mT, 7 propellers of 74 mm diameter. These components were enclosed at the center of wind turbine rotate around copper line no.40 as 4 coils, each coil 550 turns. It shows that, the distance between blower and the pico wind turbine of 8 cm obtained the wind speed 7.14 m/s, the PPWTPE rotated of 855 rpm. The magnet was rotated around the 4 coils and induced the accelerating voltage of 4.9 volts and accelerating current 17.52 mA in 4 coils. The induced accelerating current from 4 coils sent AC signal to bridge rectifier circuit converts AC to DC obtained voltage of 3.60 V and DC current of 14.90 mA, and the 7 LED lamps were bright. By using a derived efficiency equation of the PPWTPE, the PPWTPE has estimate efficiency of 9%.