The typical office chair isn't designed for users less than 5 feet tall, so you may notice that your child doesn't seem to fill the seat out the way an adult would. Most experts agree that kids can sit for about an hour in adult-sized chairs without any discomfort. For longer periods of sitting, it's recommended that you provide a chair that fits your child. Ergo Works offers a variety of kid sized chairs designed with the same quality and adjustable features as adult sized chairs.