How Much Soda to Buy?

If I'm understanding you correctly, you are having no alcohol at your wedding? If that's the case, I would still use that calculator. Alcohol or not, people like to have a drink in their hand. It also depends on what you're serving for food. Is this a cake and punch type reception, or are you having a meal? A meal will require a lot more drinks.

I edited to add more details, but there will be a full meal and beer, wine, and four signature drinks.

So...I'm doing various glass bottled sodas as a non-alcoholic option (matches the bottled beers...in my head), and I was having trouble with this also. I am having around 75 guests so my numbers will be off from yours but what I found was about 175 drinks, we will probably try to get closer to 200 bottles just to be safe. This number is a little lower than the calculators said because half our guest list includes absolute non-drinkers, but the other half will be drinking from the bar/water/champagne/lemondade. I used a couple of drink calculators I found online, the link I included below does have soda listed as an option. The only thing is it converts by 2-liters, so I just approximated how many small bottles are in a two liter. Hope that helps!

http://www.perfect-party-planning.net/drinks_calculator.html

Just saw your update...we are having beer, wine, and champagne and half of our guest list is non-drinkers (due to religious reasons). So that half will be doing sparkling cider, lemonade, water and the soda. That is what I based my calculations on. edited for clarity

Double post... -_-

Thank you Michelle, that website is very helpful.