The calibration processing algorithms currently in effect for the GOES-8 and -9 imagers and sounders are described. The algorithms have been changed since the launch of GOES-8. Smoothing of the calibration slopes has been instituted to suppress the effects of noise in the blackbody sequences. In the visible channel, the signal, originally transmitted to users in absolution counts, is now provided relative to the signal from space. The operational calibration equations were generalized to eliminate errors caused by the variation of the reflectances of the instruments' scan mirrors with east-west scan position, which was discovered after the launch of GOES-8. We are in the process of developing processing changes to mitigate the effects of two other anomalies--the appearance of east-west stripes in the infrared images from the imagers; and erroneous calibrations around midnight during six months of the year, caused by the presence of unwanted radiation from hot components of the imagers' and sounders' telescopes during the calibration sequences. Instructions are given on how to convert the counts in the GVAR data stream to radiances, temperatures, and mode-A counts.