Tipping practices can vary based on cultural norms and personal preferences, but in the United States, it is customary to tip delivery drivers around 15% to 20% of the total bill before taxes for food delivery services. In this case, for an $80 pizza delivery, a tip of 15% would be $12, and a tip of 20% would be $16.
You can adjust the tip amount based on factors like the quality of service, weather conditions, or distance traveled by the delivery driver. Tipping is seen as a way to show appreciation for the service provided. If the delivery driver goes above and beyond or if you feel particularly generous, you can tip more than the standard percentage. Conversely, if the service was poor or there were issues with the delivery, you may choose to tip less or not at all, but it's generally considered polite to give some tip for the service rendered.