Here’s a well-rounded list you can go off of when deciding the vodka to whisky amount you’ll need, assuming you buy 15 bottles of liquor for 100 people. If you have a speciality liquor you like consider adding that to this list as well.
In terms of mixers, plan on having the following for 100 guests:
4 Liters Club Soda or Seltzer
9 Liters Ginger Ale
13 Liters Coke
3 Liters Diet Coke
11 Liters Lemon-Lime Soda (Sprite)
3 Quarts each of any juice you want (plan on at least having orange, cranberry, and pineapple)
2 bottles each of sour mix, grenadine, simple syrup, and bitters.
1 bottle each of dry and sweet vermouth
1/2 lemon/lime per guest (pre-sliced)
2 olives and cherries per guest
Fall, Winter and Spring weddings: People tend to drink more red wine at indoor weddings in the fall, spring and winter. As a rule, have a mix of about 50% of red wine for this type of wedding.
Summer and Outdoor weddings: Outdoor weddings on hot days will have people drinking more white wine. Consider a mix of 30% each of all 3 styles of wine. On the other hand, you might also think about serving rosé, especially if you’re serving fish or seafood.
So if you’re buying 70 bottles of wine, your shopping list for an evening wedding inside might look like:
12 sparkling (not including extra bottles if you’re having a toast)
(100% of guests) = 100
(Number of glasses per bottle of champagne) = 5