Outflows driven by active galactic nuclei ( AGNs ) are often invoked as agents of the long-sought AGN feedback . Yet , characterizing and quantifying the impact on their host galaxies has been challenging . We present Gemini Multi-Object Spectrograph integral field unit data of 6 local ( z < 0.1 ) and luminous ( L _ { \mathrm { [ OIII ] } } > 10 ^ { 42 } erg s ^ { -1 } ) Type 2 AGNs . In the first of a series of papers , we investigate the kinematics and constrain the size of the outflows . The ionized gas kinematics can be described as a superposition of a gravitational component that follows the stellar motion and an outflow-driven component that shows large velocity ( up to 600 km s ^ { -1 } ) and large velocity dispersion ( up to 800 km s ^ { -1 } ) . Using the spatially resolved measurements of the gas , we kinematically measure the size of the outflow , which is found to be between 1.3 and 2.1 kpc . Due to the lack of a detailed kinematic analysis , previous outflow studies likely overestimate their size by up to more than a factor of 2 , depending on how the size is estimated and whether the [ OIII ] or H \alpha emission line is used . The relatively small size of the outflows for all 6 of our objects casts doubts on their potency as a mechanism for negative AGN feedback .