Why a range, never a date
This isn't a countdown. It holds your child's current growth percentile steady and walks the CDC's own stature-for-age tables forward, widening the window the farther out the event is — a growth spurt eighteen months out is a lot less certain than one six weeks away, and the range says so honestly instead of pretending otherwise.
Nothing here is a promise. Kids drift between percentile channels, catch up late, or grow in bursts. The one guarantee: measure at the ride before you count on it — shoes on, and cast members are strict about it for good reason. If you just want to know what's clear today by height alone, Can My Kid Ride? covers every attraction across all ten U.S. Disney and Universal parks.
Built on the same CDC growth-chart method (and the same attraction data) as our personalized printable growth chart, so the free tool and the paid one can never tell you two different things.