Car seat & booster law
New Hampshire
Verified · JUN 2026Quick answer · New Hampshire
A car seat or booster is required until your child is 7 years old or taller than 4'9".
A child under 7 and under 57 inches must be in a child restraint system. From age 7, or once 57 inches, a seat belt is allowed.
Car seat law checker
The legally required restraint, by state.
General information, not legal advice.
SeatCheckerRequired vs recommended
What the law enforces, and what pediatricians advise. They are not the same.
The law requires
Minimum, or it's enforceable
- Rear-facing until
- Not specified by law
- Booster until
- Age 7 or 4'9"
- Back seat
- Not required
Pediatricians recommend
AAP — safer, not the law
- Rear-facing until
- To seat limit (often age 2+)
- Booster until
- 4'9" — typically age 8–12
- Back seat
- Until age 13
AAP guidance is a safety best practice and is separate from New Hampshire's legal minimum, which ends at age 7 or 57 inches. Pediatricians recommend a booster until the seat belt fits.
Every stage, by the law
Dual units shown throughout (in + cm, lb + kg). Rows marked Guidance are best practice, not a statutory requirement in New Hampshire.
| Stage | Age | Height | Weight | Citation |
|---|---|---|---|---|
| Rear-facing | Infant (per seat) | — | — | Guidance |
| Forward-facing | Toddler (per seat) | — | — | Guidance |
| Booster | until 7 yr | < 4'9" / 145 cm | — | N.H. Rev. Stat. § 265:107-a |
| Seat belt | 7 yr + | or ≥ 4'9" / 145 cm | — | N.H. Rev. Stat. § 265:107-a |
| Back seat | Recommended < 13 | — | — | Guidance |
- Age
- Infant (per seat)
- Age
- Toddler (per seat)
- Age
- until 7 yr
- Height
- < 4'9" / 145 cm
- Age
- 7 yr +
- Height
- or ≥ 4'9" / 145 cm
- Age
- Recommended < 13