Enter your child's age, weight and height, plus your seat's limits if you know them, to see the recommended car seat stage based on American Academy of Pediatrics (AAP) best-practice guidance: rear-facing, forward-facing harness, booster or seat belt.
Last updated:
Your child
Units
yr
mo
lb
in
kg
cm
Only matters for booster-age children (see the checklist below).
Your seat's limits (from its label, lb / in)
lb
Many convertible seats allow 40–50 lb rear-facing.
in
Or until the head is within 1 in of the shell top.
lb
in
Or until shoulders are above the top harness slots.
Enter your values to see the result.
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How to use the Car Seat Stage Finder
Enter your child's age in years and months.
Enter weight and height in lb and inches or kg and cm.
Check your seat's label and enter its rear-facing and forward-facing harness limits (typical values are filled in).
For booster-age children, try the 5-step test in your car and tick the box if they pass.
Press Find car seat stage to see the stage, the seat type and when to move on.
The four car seat stages at a glance
Stage
Who it is for
Move on when
1. Rear-facing seat
All babies and toddlers, from birth
The child reaches the seat's rear-facing weight or height limit (often 2–4 years). Never before age 1.
2. Forward-facing harness
Children who have outgrown rear-facing
The child reaches the harness weight or height limit (many seats 65 lb or more).
3. Belt-positioning booster
Children who have outgrown a harness, usually at least 4 years and 40 lb
The adult seat belt fits properly, typically about 4′9″ (57 in) and 8–12 years.
4. Seat belt
Children who pass the 5-step belt fit test
Ride in the back seat until 13.
How the finder decides
The finder compares your child's weight and height with the limits you enter, one stage at a time. If either measurement is over the rear-facing limit and the child is at least one year old, it checks the forward-facing harness limits. If the harness is outgrown, it checks booster readiness (age 4 and 40 lb is the usual booster minimum), and finally seat-belt fit: at least 8 years, about 57 inches tall and a passed 5-step test. Typical seat limits are filled in, but every seat is different, so use the numbers printed on your own seat's label.
Installation tips
A correctly installed seat should not move more than 1 inch side to side or front to back at the belt path.
Harness straps should be snug: you should not be able to pinch a fold of strap at the shoulder. Place the chest clip at armpit level.
Rear-facing harness straps go at or below the shoulders; forward-facing straps go at or above the shoulders.
Remove bulky coats before buckling in; put a blanket or the coat over the harness instead.
Replace a seat after a moderate or severe crash, and check its expiration date.
Frequently asked questions
When should I turn my child's car seat forward-facing?
The AAP recommends keeping children rear-facing as long as possible, until they reach the highest weight or height allowed by their seat's rear-facing mode. Most convertible seats let children ride rear-facing until at least age 2, and many to age 3 or 4 (often 40 to 50 lb). Babies under 1 year should never ride forward-facing.
When can my child switch to a booster seat?
Once they outgrow the weight or height limit of their forward-facing harness seat, which for many seats is 65 lb or more. Most boosters also require a child to be at least 4 years old and about 40 lb, and mature enough to sit properly for the whole trip. Moving to a booster early is less protective than a harness.
When can a child stop using a booster seat?
When the adult seat belt fits correctly without it, which usually happens when the child is about 4 feet 9 inches (57 inches, 145 cm) tall and between 8 and 12 years old. Use the 5-step test: back flat, knees bent at the seat edge, lap belt on the thighs, shoulder belt across the chest and the child can stay in that position.
When can my child sit in the front seat?
The AAP advises that all children younger than 13 ride in the back seat. Front air bags are designed for adults and can injure younger children.
Does my child have to switch stages at a certain age?
No. Age gives a minimum, but the main triggers are your seat's weight and height limits and, for seat belts, proper belt fit. Moving to the next stage is a step down in protection, so the advice is to wait until a limit is reached.
Is this the same as my state's car seat law?
Not always. State laws set minimum legal requirements and differ from state to state, while AAP guidance describes best practice, which is often stricter. Follow your seat's manual and check your state's law too.
How do I know my child has outgrown the rear-facing height limit?
Check the label. Many seats also say the child's head must be at least 1 inch below the top of the seat shell or headrest when rear-facing. In forward-facing harness mode, the child has outgrown the seat when the shoulders are above the top harness slots or the tops of the ears are above the shell.
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