How to know if your toddler is ready for a booster seat

Many parents who diligently buckle their babies and toddlers into child safety seats are inadvertently putting them at risk when they get older.

In many states, children are required by law to be restrained in seats only until the age of 3. This often attributes to the incorrect assumption that older children are properly protected by regular seat belts. The fact is that older children need to use a booster seat to be safe.

Seat Use Chart

“Booster seats are the most under used seat out there,” says Bob Wall, Traffic Safety Officer for Fairfax County, Va.

“Parents think it’s a rite of passage — they’re growing up now, so they’re ready for a seat belt. They think that if the law says it’s OK, then it’s OK. But the truth is that the laws are passed by people who don’t really understand the issues.”

According to the National Highway Traffic Safety Administration (NHTSA):

Children who cannot sit with their backs straight against the vehicle seat back cushion, with knees bent over a vehicle’s seat edge without slouching, are not big enough for adult seat belts.

On a small child, the adult lap belt rides up over the stomach and the shoulder belt cuts across the neck. In a crash, this could cause serious or even fatal injuries.

“Cars are designed for an adult world, and a booster seat makes a child fit into an adult world correctly,” says Wall.

Using a booster seat positions the seat belt properly across a child’s body so it can work safely and effectively.

In addition, a booster seat allows the child’s legs to bend normally. This is more comfortable for the child, lessening the chance of slouching, which can cause a belt to fit poorly.

[Tweet “If he can’t sit with his back straight against the vehicle seat back cushion, he’s not ready.”]

One mom learns the importance of toddler booster seat

A close call in 1999 convinced Christine Guarino of the importance of using proper safety restraints for her children.

When the Germantown, Md. mom visited a car seat check, officials made a recommendation concerning her 5-year-old son Stephen’s seat.

“We had a booster seat with the 5-point harness, but one mistake that most parents make is that once the child reaches 40 pounds, that 5-point strap needs to be taken off and they need to use the seat belt with the booster seat instead,” says Guarino.

“Stephen was around 44 pounds, and they felt that according to the manufacturer’s advice the straps wouldn’t hold him properly. So we took the straps off and used the seat as a belt-positioning booster seat.”

In a booster seat.The very next day, Guarino was grateful that she took the advice to heart.

“I had just picked him up at school and we were heading for Grandma’s house. Not far from there, a big dump truck ran a stop sign and hit us on the passenger side — witnesses said it opened the side of our van like a can of sardines. The truck ended up with its front end inside our mini van, and Stephen’s right foot was resting up against the bumper of the truck.”

Unfortunately, that side of the mini van, window and all, collapsed down on his head. But the whole point is that he was buckled up properly into his booster seat, so he wasn’t thrown out of it. Several policemen who investigated the collision said that if he was not in a booster seat, they don’t see how he could have survived the crash.

Since that incident, booster seats have become a main priority for Guarino.

Besides working on legislation for booster seat laws, she has become a certified safety seat educator, speaking at schools, clubs and churches. In addition, she volunteers at safety seat checks to help save children from unnecessary injuries.

Booster Seat Safety Recommendations

It is important for parents to know the safety recommendations.

According to a NHTSA brochure, children should be kept “in a forward-facing safety seat with full harness as long as the child fits in this seat.”

Generally, children outgrow regular child safety seats when they reach about 40 pounds or when they have grown too tall for the seat. Two indicators are if the child’s ears are above the back of the car seat or the shoulders are above the highest strap slots.

Once the child outgrows the infant car seats, booster seats are needed to fill in the gap until the child is big enough for a regular seat belt. Generally, this is when the child is about 80 pounds and around 4 feet, 9 inches tall (usually between the ages of 4 and 8).

[Tweet “Once the child outgrows the infant car seats, booster seats are needed to fill in the gap until the child is big enough for a regular seat belt.”]

For a seat belt to fit properly, the lap belt should rest low across the upper thighs, with the child sitting straight against the seat back. The shoulder belt should rest snugly on the shoulder across the chest. Shoulder belts should never be placed behind the child or under the arm, which offers no upper body protection and can result in severe injuries.

Proper seat belt fit.A NHTSA study reports that restraint use falls from 91 percent before age 4 to 68.7 percent after age 4. In addition, the group estimates that only 6.1 percent of children of booster seat size are actually using one. This contributes to the fact that traffic crashes are the leading cause of death for children of every age from 6 to 14. Children in this age group need to be protected.

“A lot of people ask me about the law, and I ask them which law they mean — the law of the land or the law of physics,” says Wall. “The law of the land changes, but the law of physics is constant. Your child is going to be injured or killed in a crash if he or she is not buckled up properly.”

Types of Car Booster Seats

High back booster with 5-point harnessDifferent booster seats.

This type of booster is good for providing head and neck protection in back seats that are not equipped with head restraints.

The 5-point harness provides full body protection for children up to 40 pounds, and then can be removed to convert the seat to a belt-positioning booster.

Belt-positioning booster car seat

The belt-positioning booster seat uses the vehicle lap and shoulder belts for restraint for children 40 to 80 pounds. Most have a clip or strap designed to hold the shoulder belt properly in place.

Shield booster

This type of booster may be used in vehicles that are not equipped with shoulder restraints in the back seat. It offers protection when using a lap belt, but only for children up to 40 pounds, and most experts recommend keeping the child in a full harness to 40 pounds.

When the shield is removed, the booster allows a child between 40 and 80 pounds to be safely restrained with the vehicle lap and shoulder belts. This type is a good choice if the vehicle’s seat back is higher than the child’s ears, eliminating the need for the added protection of a high back booster.

Check the Label

All booster seats are required by law to comply with the same standards as regular child safety seats. The label should state: “This child restraint conforms to all applicable U.S. Federal Motor Vehicle Safety Standards.”

“Add-on Devices” or SeatBelt Positioners

Add-on devices advertised to improve belt fit for older children are not covered by government standards. They may make the shoulder belt more comfortable, but may put too much slack in the shoulder belt or cause the lap belt to ride up dangerously. According to NHTSA, these devices should never be used in place of booster seats.

Don’t Use Substitutes

Never use pillows, books, towels or other objects to boost a child, since they can easily slide around.


Always send in the seat’s registration card so the manufacturer can contact you if there is a recall. If your seat is not registered, you can check for recalls by calling the DOT Auto Safety Hotline at 1-888-DASH-2-DOT or by visiting the NHTSA Web site.

You will need to know the model number and manufacture date of the seat — information that is printed on a label somewhere on the seat. Second-hand seats with missing labels should not be used, since there is no way of knowing if there is a recall.

Used Seats

If you decide to use a second-hand booster seat, it is important to know that it has not been involved in a crash.

Small defects are not always apparent when you inspect a seat, but can be significant enough to reduce the seat’s protection.

In addition, most manufacturers recommend that seats be retired after five years of use. If you do not know the seat’s history, it is better to buy a new one.

Photos from the National Highway Traffic Safety Administration. Used with permission.

Leave a Comment