Pool Gate Latch Height: The Placement at Which a Latch Leaves a Young Child's Reach Without Leaving an Adult's

A gate between a garden and a swimming pool must be operable by every adult and by almost no young child, and the dimension that decides the matter is latch height. This study models a child's chance of reaching and operating a latch as a logistic function of height, with a midpoint of 1.38 m for five-year-olds and 1.43 m for six-year-olds, both stated values, and asks where the chance falls below one percent. At 1.35 m a five-year-old still succeeds 66.08 percent of the time; at 1.5 m the figure is 6.5 percent. The one-percent level for five-year-olds is reached at 1.587 m, and for six-year-olds at 1.637 m, which sits close to the 1.65 m level above which shorter adults begin to find a latch awkward. The window between child resistance and adult convenience is therefore narrow but real: a latch placed between about 1.60 m and 1.65 m, ideally shielded so that reach alone is not enough, satisfies both sides of the requirement on the stated model. SIMULATED, NOT MEASURED.