Most babies first attempt to climb stairs between 7 and 9 months old, right around the time they learn to crawl. At that age, they’ll try going up on hands and knees rather than coming down. From there, stair skills develop gradually, with most children not walking up stairs until around age 2 and not navigating them with full confidence until age 4.
The First Attempts: 7 to 9 Months
Once a baby can crawl, stairs become irresistible. Babies at this stage will almost always try to go up rather than down, because climbing up on all fours feels like a natural extension of crawling. Going down requires a completely different skill set: the ability to move backward, judge depth, and control speed against gravity. That asymmetry is important to understand, because a baby who can scramble up three or four steps may have no idea how to get back down safely.
These early climbing attempts are pure exploration. Babies at 7 to 9 months don’t have the balance or judgment to navigate stairs independently, so any access to a staircase at this age needs direct, hands-on supervision.
Upright Stair Walking: 19 Months to 2 Years
Between about 19 and 21 months, toddlers typically start walking up stairs while holding a railing or an adult’s hand. At this stage, they use a technique sometimes called “marking time,” where both feet land on the same step before moving to the next one. It’s slow and deliberate, but it’s a real milestone in balance and leg strength.
The CDC lists walking (not climbing) up a few stairs, with or without help, as a milestone by age 2. This lines up with what most pediatric sources describe: children refine their independent walking first, then apply that stability to stairs. If your toddler is still preferring to crawl up stairs at 18 months, that’s completely normal. Walking up requires significantly more single-leg balance than walking on flat ground.
How Stair Skills Progress After Age 2
Stair navigation keeps developing well into the preschool years. Here’s the general timeline:
- Around age 3: Children typically go up stairs with alternating feet (one foot per step, like an adult) but still use the two-feet-per-step method going down. Going down remains harder because it demands more controlled deceleration and a better sense of where their feet are in space.
- Around age 4: Most children can go both up and down stairs with alternating feet and without holding a railing. This is the point where stair navigation looks essentially adult-like.
The gap between going up and coming down persists for a long time. If your 3-year-old climbs up confidently but insists on scooting down on their bottom, that’s developmentally appropriate.
When to Pay Attention to Delays
Children develop at different speeds, and being a few months behind a milestone chart is rarely a concern on its own. That said, a child who is falling frequently or still struggling significantly with stairs at age 3 may benefit from a developmental screening. Pediatric guidelines flag frequent falling and persistent trouble with stairs at age 3 as a reason to check in with your child’s doctor. Difficulty with stairs at that age can sometimes point to broader gross motor delays that respond well to early support like physical therapy.
Keeping Stairs Safe at Every Stage
Baby gates are the single most important safety measure once your child starts crawling. The rules for gates differ depending on where they go. At the top of stairs, you need a hardware-mounted gate that screws into the door frame or wall. Pressure-mounted gates, which stay in place through friction, are fine at the bottom of stairs or in doorways between rooms, but they can be pushed out of position at the top, which creates an obvious fall risk. Gates that swing outward should never be used at the top of a staircase.
When choosing a gate, look for a few specifics. The gate should be at least three-quarters of your child’s height. Vertical slats should be no more than 2⅜ inches apart so a child’s head can’t get trapped between them. The gap between the bottom of the gate and the floor should be under 2 inches to prevent a child from sliding underneath. Avoid gates with horizontal bars or decorative cutouts that give a child footholds for climbing. A certification label from ASTM or JPMA indicates the gate meets current safety testing standards.
Practicing Stairs With Your Child
Rather than keeping your child away from stairs entirely, supervised practice helps them build the skills they’ll need. Start by letting your crawling baby go up two or three carpeted steps while you stay right behind them, close enough to catch them if they lose their balance. Teaching a baby to come down stairs backward on hands and knees is one of the most useful early skills you can introduce, since their instinct will be to go forward and face-first.
As your toddler starts walking upright on stairs, position yourself below them when they’re going up (to catch a backward fall) and above them when they’re coming down. Let them hold the railing whenever one is available at a reachable height. Over time, they’ll shift from needing your hand to needing just the railing to needing nothing at all. That full progression from first crawling attempt to independent, alternating-foot stair walking spans roughly three years, from around 8 months to about age 4.