Laser weapon systems, unlike conventional weapons, are heavily dependent upon the ever-changing atmospheric conditions in their employment theater. In order to understand the operational effectiveness of a laser weapon, the performance limits due to atmospheric conditions need to be understood. ANCHOR, a laser performance scaling code developed at the Naval Postgraduate School, is one such code used to model a lasers effectiveness for a variety of atmospheric conditions. This thesis focuses on the calibration of ANCHORs thermal blooming model. In the absence of turbulence, thermal blooming is generally well understood and the thermal blooming Strehl ratio is well defined. When turbulence is coupled with thermal blooming, however, the thermal blooming Strehl ratio is exceedingly difficult to quantify using scaling codes. This thesis calibrates ANCHORs thermal blooming model using the full wave propagation code TBWaveCalc by adjusting the coefficients of an analytical formula to best fit the TBWaveCalc results over a wide variety of initial conditions.