Bhutan’s electricity is 230 Volts and alternating at 50 cycles per second. You will need a voltage converter if your electrical device does not support 230 Volts at 50 Hertz.
Electrical outlets (sockets) in Bhutan can usually three types of plugs:
Plugs with three rounded pins arranged in a triangle (Type D – Indian 5 amp BS-546)
Plugs with two rounded pins (Type C – European CEE 7/16 Euro plug) and
Plugs with two parallel flat pins and a ground pin (Type G – British BS-1363)
If your electrical plug doesn’t match the shape of these sockets, you have to carry a voltage converter to use a device that does not accept this kind of supply and travel plug adapter in order to plug in.