A child can be out of a car seat and start using a seat belt alone when they reach either 12 years of age or a height of about 135-150 cm (about 4 feet 5 inches to 4 feet 11 inches), whichever comes first. The specific criteria include the child being able to fit the seat belt properly—meaning it rests across the collarbone and hips, not the stomach, and they can maintain correct posture with their back against the vehicle seat, knees bent, and feet touching the floor. Children are generally required to use a child car seat or booster until these conditions are met for safe seat belt use. Booster seats are typically used from about 4 years old until around 12 years old or until the child outgrows the booster by height or weight limits. In addition, car seat stages progress typically as follows:
- Infants use rear-facing car seats until they reach the height or weight limits of the infant seat, usually up to around 1 to 2 years of age.
- Toddlers and young children transition to forward-facing car seats and then booster seats as they grow, staying rear-facing as long as possible (often until at least age 4).
- Booster seats are used until the child meets the "5-step test" for proper seat belt fit and safety, which is usually at age 8 to 12 or when the child reaches about 135-150 cm in height.
Children should remain in the back seat until at least age 12 for safety reasons. The exact timing depends on the child’s size and the car seat manufacturer’s height and weight limits. Always follow the specific car seat manual guidelines and local laws for the safest timing to transition out of a car seat. This aligns with guidelines from authoritative sources including UK and US standards, European regulations, and safety recommendations from organizations such as the NHTSA.
