School-Age Children: Booster Seats & Seat Belts | Injury and Violence Prevention Program | UC Davis Health

• Combination seat – using a lap-shoulder belt and internal harness removed.
• High-back booster seat – must be used when a vehicle does not have a head restraint.
• Backless booster seat – suitable for use when a vehicle has a head restraint in place.

Safety Tips

• Children are ready to use a booster seat when they weigh 40 pounds or have outgrown their five-point harness. Some child safety seats have a harness weight limit beyond 40 pounds. It is preferable to continue using the five-point harness until your child reaches that weight limit or has outgrown the seat.
• Must be used with lap and shoulder belts.
• The shoulder belt fits snugly across the chest and rests on the shoulder.
• The lap belt lies snugly across the upper thighs and below the hips.
• Secure the booster seat in the back seat of the vehicle.
• When a child is not in the booster seat, secure the booster with the seat belt to ensure the loose seat does not cause injury.
• Manufacturer’s weight and height limits vary. The minimum weight ranges from 40 to 50 pounds, and the maximum weight ranges from 80 to 120 pounds. Height limits vary from a minimum of 40 inches to a maximum of 59 inches. Be sure to follow instructions. Always follow the car seat manufacturer’s instructions and the vehicle’s guidelines to ensure the seat is used properly.

Moving from Booster to Seat Belt

Older children are ready to move from their booster seats to a regular seat belt when they can pass the “5 Step Safety Belt Test”.

5 Step Safety Belt Test
A child must meet all of the following conditions for the entire trip:

1. Sits all the way back against the seat.
2. Knees bend over the edge of the vehicle seat.
3. The shoulder belt crosses the center of the chest and shoulder, not the neck.
4. The lap belt is as low as possible, touching the thighs.
5. Can maintain this position for the entire trip