It’s hard to pinpoint the entire cost of a 100 person wedding. For the venue and reception alone, the average cost is around $7,000. Keep in mind this does not include other costs, such as attire, entertainment, and alcohol. A 100 person wedding is fairly common and not considered small or large. The rough average cost of a wedding in the United States is around $28,000-- but averages don’t tell you about outlier spending, nor do they dictate how much you should spend on your wedding.