What’s the 5 Step Seatbelt Test?

According to the NHTSA, kids start using the booster seat between the ages 4 and 7 and should continue using it until about age 12-13.

However, not all 8-years-olds are ready to start using the seatbelt because kids are individuals and don’t develop at the same rate or in the same way. Nor do seatbelts fit exactly the same way in every car and in every spot inside the vehicle.

Related: What’s a booster seat and what does it do?

Fortunately, there’s a simple “experiment” that can help you determine whether your kiddo is ready for the adult seatbelt. And this is the 5-step seatbelt test.

But what’s the 5 Step Seatbelt Test? How do I perform this test and why is it important? This post answers these two critical questions plus a few more.

The 5-Point Seatbelt Fit Test and Why It Matters

You can travel around with your child in a poorly fitting seatbelt, completely unrestrained, or even lap-carry them out in the front passenger seat. But that’s NOT safe. The best thing to do is to restrain the child with the right safety device and use it the way it’s supposed to be used.

An incorrectly fitting seatbelt can’t be counted on when it comes to providing protection against crash impacts. Where a child is too small for the seatbelt, it’s best to continue restraining them in the booster seat or a higher-weight-limit forward-facing car seat.

The 5-point seatbelt fit test is a method used by in-the-know parents everywhere to determine whether a child fits right in seatbelts. If a child meets all 5 seatbelt fit requirements, they’re deemed mature enough to use it and can then stop using the booster seat and start using the sealtbelt.

How to Perform the 5-Step Seatbelt Fit Test

Would you prefer to watch the 5-step test rather than read about it? No worries, watch the video below to learn how to know for sure whether your child is ready to move out of the belt-positioning booster seat and into the seatbelt.

YouTube video

Before I say anything further, let’s get this out of the way: I didn’t invent this test. Nor did anyone I know. I learned it from the Car Seat Lady and Safe Ride 4 Kids. Now that that’s now out of the way, below is how to perform this all-important fit test.

According to the Car Seat Lady, you can move your kiddo from the booster seat to the seatbelt if you can answer yes to ALL 5 questions below:

1.Can your child seat comfortably in the adult seat with their back pressing against the seat?

2.When the child is seated in the above position, do their knees bend just around the edge of the adult seat?

3.How does the lap belt fit? Does it lie flat across the belly of the kiddo, or does it lie nice and flat across the upper things/around hip bones?

4.How does the shoulder belt fit the child? Does this belt sit nice and flat between the neck and the shoulder or does it place too far from the neck or from the shoulder?

5. Does the child seat nice and comfortably throughout the ride and without slouching at all?

If you can say yes to ALL of the questions above, there’s a decent chance that your youth is ready to shift to the adult seatbelt.

Why is slouching a bad thing?

2 Reasons Why Your Kid Shouldn’t Slouch in the Seatbelt

1. The seatbelt moves out of position, sitting across the belly instead of across the upper thighs.

The trouble with slouching is that it positions the lap belt across the tummy instead of leaving it sitting across the upper things or around the hip bones. The child doesn’t sit straight up, and if they’re involved in a car accident, crash impacts end up on a soft and vulnerable belly instead of on the tougher part of the body, the hip bones.

Here’s another reason slouching in a seatbelt is a bad idea:

2. Slouching causes the seatbelt to have more slack and loosen up.

When the young passenger slouches instead of seating up straight, the seatbelt does loosen up. The seatbelt somehow lengthens, and there’s more slack on it.

During a crash, the seatbelt might allow your kid to keep moving forward until their noggin finally hits the seat in the front. When they collide with the seat in the front, the reaction from the impact forces the neck backwards, something undesirable.

Why Should the Legs Bend Over the Edge of the Seat?

In a booster seat, the legs of the child passenger naturally bend over the edge of the seat. But when you get the passenger out of this seat and into the seatbelt, they might not fit exactly the same way.

To avoid slouching while in the seatbelt, which can be pretty dangerous, the legs need to be tall enough that they should bend around the lower end of the seating area.

Seatbelts Aren’t for Young Children; They Are for Adults

You heard right: seatbelts aren’t designed for use by kids. They’re a safety restraint system for adults and don’t fit young kids properly. For this reason, you need to be absolutely sure that your child can safely use the vehicle’s seatbelts before switching completely from the booster seating mode. And this is where the so-called 5-point safety test for seatbelts come into play.

When Should Children Start Using Adult Seatbelts?

Different states in the US have different seatbelt requirements. Many states want users to be at least 57″ or 4’9″ tall or at least a certain weight. The weight should be at least 80 pounds according to the Department of Transportation of Mississippi. Other  insist that kids reach a certain height and weigh a certain weight number.

According to the, kids are typically between 10-12 before they can comfortably, securely, and safely fit in a seatbelt.

But this doesn’t in any way mean that all 10-year-olds or even 12-year-olds will fit properly in the seatbelt. Again, the ONLY way to be sure that your kiddo can and will use your vehicle’s lap belts and shoulder belts safely and securely is to conduct the so-called 5-point seatbelt fit test.

Don’t Get Your Kid Out of the Booster Seat Too Soon

There are two mistakes many parents make. The first mistake is they get kids to start forward-facing way too soon when all experts agree that one should rear-face as long as reasonably possible.

The second mistake many parents and caregivers make is introducing children to a booster seat or seatbelt before they’re mature enough for it. In either situation, you’re riding around with a child who isn’t safely restrained and that’s not OK.

Kate Carr, former president at Safe Ride for Kids, once noted that parents (obviously not everyone) get kids out of the booster seat too early. The majority of parents guilty of this “sin” had absolutely no idea about seatbelt height and weight requirements in their state.

Also, a bunch of parents move their kids out of booster seats into the adult seatbelt earlier than they should because the kid felt they were too grown for the booster seat.

I mean, a booster seat is still a car seat, and the BIG girl or boy no longer wants to use it. Mommy, I can’t ride in the booster seat anymore can’t you see I’m all grown and unfit for a baby car seat?

NHTSA and Consumer Reports Seatbelt Readiness Data

But is there any data showing that parents discontinue booster seat use way too soon? Yes! Consumer Reports and the National Highway Traffic Safety Administration carried out a survey in 2015 that led to interesting findings.

The survey revealed that over 25 percent of children aged between 4 and 7 move out of the booster seat sooner than they actually should.

While some 8 year-olds may be tall and grown enough for the seatbelt, most are not. Safe Ride 4 Kids notes that the vast majority of kids aren’t mature enough for the seatbelt until ages 10-10. But it’s best to use these age numbers as a starting point rather than a hard-and-fast seatbelt rule.

The best trick to really know if your child can safely be restrained with the adult seatbelt is to perform the 5-point car seatbelt test.

The Rules May Be Clear, But This Doesn’t Always Help

When researching for this post, I had trouble finding any one credible source that clearly stated what the correct seatbelt age and height numbers are. A bunch of states have age 8 as the minimum requirement a kid has to satisfy before they move out of the booster seat.

Some states say that no one should start using the seatbelt before they’re 57″ or 4’9″. Other states indicate a weight requirement or a height requirement and don’t insist on fulfilling both. There’s what the law says and recommends and then there’s what’s in your kid’s best interests.

In my experience, not many kids 57″ tall fit in seatbelts without a problem. But here’s a weird observation I’ve made: a child may 5-step in one seat and fail the test in a different seat in the same vehicle. I’ve seen kids who fit in the seatbelts of one vehicle but couldn’t use the seatbelts in a different vehicle. It’s strange, but it happens and that’s OK.

Final Thoughts on Transitioning to a Seatbelt from a Booster Seat

There’s no standard answer that works for every child, but if your kiddo stands 4’9″ or taller, it’s time to test if they’re developed enough for the adult seatbelt. Being 4’9″ tall is no guarantee that the kid will pass the 5-point test, but it’s a sign that they’re ready to take the test.

Some kids and even adults may not pass this test even after several trials. Where this is the case, they can try using an adjustable seatbelt, move to a different spot in the car (especially the third row), or ride in a different vehicle whose seatbelts fit better.

Author: Joe Waweru

As a medical professional practicing in the United States, Joe Waweru medically reviews every piece of relevant content at, but nothing he says here should be construed as medical advice of any kind.

Joe Waweru

As a medical professional practicing in the United States, Joe Waweru medically reviews every piece of relevant content at, but nothing he says here should be construed as medical advice of any kind. He's also an entrepreneur of some sort, but he prefers to keep this under wraps. <a href="Visit Joe's Facebook Profile here

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