There are a few ways that you can tell if your wheels are out of round. One way is to look at the tire tread. If the tread is wearing unevenly, it's a good indication that the wheel is out of round. Another way to tell is by looking at the sidewall of the tire. If the sidewall is bulging or leaning to one side, it's another sign that the wheel is out of round. Finally, you can check for even wear across all four tires. If one tire is significantly more worn than the others, it's likely because the wheel is out of round and causing an imbalance.