According to reviews, the sizing can run both small and big. It is recommended to go by the manufacturer's size chart: If you are 5ft 5" to 5ft 9" and you weigh between 150-175, we recommend you order a size Medium. If you are 5ft 10" to 6ft and you weigh between 175-190, we recommend you order a size Large. If you are 6ft to 6ft 2" and you weigh between 190-210, we recommend you order a size X-Large. If you are 5ft 10" to 6ft 5" and you weigh between 200-220, we recommend you order a size 2X-Large. If you are 5ft 10" to 6ft 5" and you weigh between 230-245, we recommend you order a size 3X-Large. If you are 5ft 10" to 6ft 5" and you weigh between 250-265, we recommend you order a size 4X-Large. If you are 5ft 10" to 6ft 5" and you weigh between 275-290, we recommend you order a size 5X-Large. If you are 5ft 10" to 6ft 5" and you weigh between 300-320, we recommend you order a size 6X-Large.