Sizing is the single thing that decides whether a kids table and chairs gets used or ignored, and it matters more than brand, colour or price. The principle furniture designers and early-childhood educators use is the 90-90-90 rule: a child should sit with knees, hips and elbows each bent at roughly a right angle, feet flat on the floor, and forearms resting comfortably on the tabletop without hunching or reaching up. When a child sits like that they can settle and focus; when they're perched on something too big, they fidget, slide off, and give up on the activity.
Two measurements make that happen: the chair seat height (floor to the top of the seat) and the gap between the seat and the underside of the tabletop. As a general guide that gap should be around 18-20cm (7-8 inches) so there's room for legs and a comfortable arm position. The most common question we're asked is simply what size to get — so rather than organise this range by brand, we group it by how it's used and sized, and the age-by-age guide below gives you a practical starting point.