How many straws and cups are needed for a 3 hour reception for 150 guests?

Don’t forget to account for those that will not reuse their cups and straws. I would plan for each person to have 1-2 drinks during the reception each hour. So roughly enough for somewhere around 500 to 900 drinks. I know this isn’t an exact answer but hopefully it helps.

Between 800-1000 cups. Buy from somewhere where you can return extra cups. I would easily have five drinks over the course of the night. Even more if we are counting water.

I would talk to your caterer or bar tender. Better to have too many than not enough.