But there's a big discrepancy here: The bride's parents give about $12,000 (43% of the bill) and the groom's $7,000 (24%). So, the bride's family pays about twice the amount. Traditionally, the bride's family is expected to pay for the venue and the reception, which usually ends up being over half of the total bill. With the average U.S. wedding costing about about $35,329, according to a survey from The Knot , it's no wonder that 10% of families end up spending retirement money to pay for their children's weddings. (Educated guess: Most of them are families of brides.) Additionally, one-third of parents say they spent more on their kids' wedding than they had planned. About a quarter said they started saving in advance.