When you buy through links on our site, we may earn a commission. Learn more here.

New Hampshire Booster Seat Laws (2023)

The state of New Hampshire legally requires children under the age of 7 years old and 57” (4’9”) tall to be secured in a car seat or booster seat.

The law does not specify type of car seat or booster seat by age, but the state does provide guidelines for child safety.

Booster Seat Requirements New Hampshire

Dad buckles his son into booster seat.

Children must ride in a booster seat (or rear-facing or front-facing car seat) in New Hampshire until they reach ONE of the following requirements:

  • Booster Seat Age: 7 years
  • Booster Seat Weight Limit: unspecified
  • Booster Seat Height Limit: 57” (4’9”)

Since New Hampshire law does not specify type of child seat by age, a child may legally use a booster seat as soon as the child meets the minimum age, height, and weight requirements for the seat.

However, the state recommends keeping children secured in car seats with separate harness systems for as long as possible, until a child reaches the height or weight limit on their forward-facing seat.

Where can I get my booster seat checked or installed in New Hampshire?

Dartmouth Health Children’s keeps a list of New Hampshire Fitting Stations with certified Child Passenger Safety Technicians on hand who can help you with the installation of a booster seat (or check your installation) by appointment.

You can find a list of Fitting Stations by county on the hospital’s Be Seat Smart NH website.

General Booster Seat Laws FAQ

Are booster seats effective?

Yes. Very.

According to the CDC, “booster seat use reduces the risk for serious injury by 45% for children age 4-8, when compared with seat belt use alone.”

When can a child use a booster seat?

A child can use a booster seat when she outgrows her forward-facing car seat with a harness.

Though the laws on front-facing car seats and booster seats differ by state, for safety’s sake your child should stay in a front-facing (harnessed) child seat until he reaches the maximum height or weight on the seat.

When can a kid stop using a booster seat?

The minimum safe height for use of a regular seat belt without a booster seat is 4’9”.

Due to this, it is recommended your child ride in a booster seat until they are at least 4’9” tall, regardless of their age.

Not all state laws support this.

Many states have minimum ages at which children may transition to regular seatbelts, no matter how tall they are.

But if you want your child to be the safest they can be on the road, you should keep them in a booster seat until they reach 4’9”.

What is the booster seat weight limit?

Different booster seats have different weight limits, typically 100-120 pounds.

But weight isn’t the main determiner of when a child should move from a booster seat to a seat belt.

Height is more important to a seat belt’s fit.

That said, your child should never ride in a booster seat once they exceed the weight limit.

The seats are designed to be safe only for those under the maximum weight.

So, if your child has outgrown the weight limit on their booster, upgrade them to a booster with a higher weight limit or make the transition to a regular seatbelt.

What’s the best booster seat?

The best booster seat is the one that will do the most effective job of keeping your child safe in the event of an accident.

According to Consumer Reports, the top-performing booster seats on the market (as of July 2022) are:

Nuna AACE

Nuna AACE

Buy at:

Graco Turbobooster Grow

Graco Turbobooster Grow

Buy at:

Peg Perego Viaggio Shuttle Plus 120

Peg Perego Viaggio Shuttle Plus 120

Buy at:

But you don’t have to buy a separate booster seat if you have a convertible car seat.

For convertible toddler-booster seats and all-in-one car seats with booster functionality, see our car seat buying guide Which Car Seat To Buy: Making Sure Your Little Ones Stay Safe On The Road.

When were booster seats invented?

The very first child seats for cars were more booster seats than car seats.

They were literally designed to “boost” children up so they could see better (and so parents could see them), but they had no built-in safety features.

Booster seats as we know them today, with their focus on transitional safety between car seats and seatbelts, have only been around since the late-1990s to early 2000s when laws requiring them started being implemented.

When did booster seats become mandatory?

Booster seats are not mandatory in all states.

Some states have younger minimum ages and no height requirements for transitioning children from child seats to seatbelts.

In those states, children can typically move directly from forward-facing car seats to regular seatbelts.

As for the states that do have mandatory booster laws, the first laws (Tennessee and South Carolina) went into effect in 2001.

Bridging the Gap Between Car Seats and Seatbelts

Car seats are designed to protect the smallest of children, while seatbelts are only safe for children over a certain height (4’9”).

Booster seats bridge the gap between the two.

While New Hampshire doesn’t require children over 7 years old to be secured in a booster seat, we recommend following expert guidelines and keeping your kid in a booster until they reach the safe seatbelt height of 4’9″.

And, before that, follow the state’s car seat laws.

For more on New Hampshire’s car seat laws, see New Hampshire Car Seat Laws.

And for more on child passenger safety in New Hampshire, see New Hampshire Front Seat Law.