While this varies from one marriage to another, the average length of a marriage in Florida and all across the U.S. is about eight years. Statistics also shows that couples are more likely to have an extramarital affair after the first two years of marriage. The age when you decided to walk down the aisle also plays a major role in determining how long your marriage will last. As a Fort Lauderdale divorce attorney Gustavo Frances has mentioned earlier, as children get older, the likelihood of divorce increases. While many couples choose to postpone their inevitable or long overdue divorce until the children turn 18 thinking that adult children are more likely to handle their parentís divorce maturely, other couples also choose to wait until their children become adults to avoid legal issues such as child custody and child support altogether.