You should consult your vehicle's owner's manual. This will give you the most accurate refrigerant capacity.
Failing that, a reliable source of information would be a repair manual specific to your vehicle's year, make, and model.
Trying to find the amount online without specific details risks overcharging or undercharging the system. Both can lead to poor AC performance and potential damage to the system. It's best to consult a qualified automotive technician for accurate information and proper servicing.