How many hors d'oeuvres do I need for a 2-hour cocktail party for 25 people?

Shoshana... one of my trademark things to do when I'm having a cocktail supper like this is to make a pot of "something" that stays in the kitchen that I bring out after the party's over for the lingerers. It usually is something built around beans (chili, red beans and rice, etc) or pasta with a veggie sauce. Something easy and inexpensive but tasty and filling.

Specifying the time in the invitation helps, but I've found some folks still arrive AFTER the witching hour! and I never want to turn anyone away.

Thanks everyone. These answers are so helpful - I appreciate everyone's thoughtfulness. ChefJune, To drink, I'm offering either champagne or a gin-based cocktail or sparkling water for the non-booze drinkers. The party is next Sunday, 6-8 but I fully expect some people to linger. I've specified the block of time in the invitation.

While the "average" IS 3-5 pieces per person, whom do you know who is "average?" So much depends upon the time of day you are serving these, and whether or not dinner is to follow.

Whatever the number you decide on, my rule of thumb is always have another "round" ready to go. You don't want to run out of food.

My "weird" observation is that folks drinking cocktails tend to eat more than folks drinking wine. So, what are you serving to drink?

whenever i see this question asked, i always want to ask the questioner if i'm invited because i will personally make those numbers meaningless by eating about four times the suggested average, if given the opportunity. that said, the rule i learned is fifteen bites per person, meaning one piece of hors d'oeuvre can equal one or more bites.

Have fun everyone!

Boulangere your answers are always so right on! Thanks to Shoshanadh question and your answer I am set for tomorrow.

The average is 3.5 pieces per person, because like it or not, some will view it as dinner. And I apologize in advance to everyone, but observed as recently as last evening, the fact is that men will eat more than women. To please everyone, perhaps think of adding fruit & vegetable platters, as well as a little something sweet. And have a lovely evening!