How well you know your guests will be a large factor determining the accuracy of your rental numbers. Are they mostly wine fans? Beer snobs? Recovering alcoholics? Under 21?
What you are serving for food will also help you determine what you need. Are you serving anything that requires use of a spoon? Do you need a complete place setting for your desired look?
Below is a table based on 100 guests of average rental quantities.
Dinner Plates: 120 Water Goblets: 100
Dinner Forks: 100 Knives: 100
Wine Glasses: 75 Beer Glasses: 50-60
Cocktail Glasses: 50-60 Napkins: 110
Coffee Mugs: 60 Spoons: 60
Dessert Forks: 100 Dessert Plates: 100
Depending on your aesthetic preferences, you can save a lot with your linens.
If you want tables to have to-the-floor linens, you are choosing the most expensive option, while 3/4 length linens will sufficiently cover table legs but allow room for feet and moving chairs - it can also save you a lot of money.
If you don't care at all about the legs showing, half-length linens are the most affordable option and still have good coverage on the areas that count. We recommend full length cloths on head tables and other tables that won't be surrounded by chairs.
Skip the chair covers. Covers can look tacky, be a lot of work, and will add about $3.50 per guest to your costs. Even though you may think the banquet chairs provided by your venue are hideous, chances are, no one will be paying attention to the chairs because most of the night they will be sitting in them. Research design blogs and magazines for other creative and more affordable ways to dress up your chairs. Or - renting nicer chairs is often cheaper!