Provided herein is a multichannel Transcranial Magnetic Stimulation (mTMS) coil device with two or more overlapping coil windings within a casing. The mTMS coil device is capable of adjusting parameters of the stimulation of magnetic and induced electric fields through the selective control of the multiple coil windings within the mTMS coil device. Additionally, provided are methods of operation including navigated TMS for adjusting parameters such as location, direction and/or orientation of magnetic and induced electric fields from mTMS coil devices.