Stacks two small blocks
Typical Timing & Development Window
Visual Timeline & Milestone Benchmarks
What these numbers mean
The average age babies first begin showing early signs of this skill. Before this, it's simply too early — there's nothing to worry about.
The midpoint age: half of babies have reached this milestone by here, half a little later. It's a typical target, not a deadline.
How spread out the timing is. About two-thirds of babies achieve it within one standard deviation of the median (the shaded band, wk 74–82). Wide bands mean a normal range of variation.
A gentle check-in point. If your baby hasn't shown this by around here, it can be worth mentioning to your pediatrician — most often it's still perfectly fine, just later.
About this milestone
The toddler successfully balances one small block on top of another without them falling over. This requires precise hand-eye coordination, fine muscle release, and spatial reasoning. It marks the transition from simple grasping to constructive, purposeful object manipulation.
- 1. Give the toddler large, easy-to-stack blocks (like wooden cubes or plastic interlocking blocks) to practice alignment.
- 2. Guide the toddler's hand gently, helping them feel the moment of release when one block is aligned over another.
- 3. Use other stackable household items, like plastic cups or small bowls, to build stacking confidence.
- 1. Avoid unsupervised stacking practice with small pieces and keep small parts out of reach.