You must consult your vehicle's owner's manual for the precise amount. The information should be in the AC system section. If you don't have the manual, you can often find a downloadable version online from a Chevrolet website or a site specializing in vehicle manuals.
Alternatively, a qualified automotive AC technician will have access to this information through their service manuals or databases. They'll also be able to accurately determine the correct amount needed for your specific Tahoe during an AC service. Trying to figure this out without proper resources is risky and could damage your system.
