General guidelines for chairs are developed by looking at international averages for children's growth. These guidelines offer a starting point when selecting furniture, but don't account for individual differences. In general, toddlers and 2-year-olds need chairs 6 to 8 inches high. Purchase 10- to 12-inch chairs for preschoolers through first grade. Upper-elementary age children need chairs that stand 14 to 16 inches high.
To determine the correct chair height for an individual child, have the child sit on a surface that allows his feet to rest flat on the floor, while the knees are at a 90-degree angle. Measure from the floor to the bottom of the seat to determine the correct height.
A properly fitted chair allows children the postural stability they need to complete fine motor tasks, such as drawing and using scissors. Children are less fidgety and may stay longer at the table. When children's feet dangle from chairs, they fatigue quickly and feel unsteady.
When buying chairs for groups of children, such as a preschool class, order at least two different sizes to account for variances in growth. Look for chairs with rounded corners, a stable base and a nonporous surface. Plastic or sealed wood is durable and tolerates sanitizing. Place a stool under large chairs so the children's feet don't dangle.