Tools · Car Seat
Washington Car Seat & Booster Checker (2026)
Enter your child's age, height, and weight to see the minimum seat stage Washington law requires and the first-offense fine (No set statutory amount). This is the legal minimum, not best safety practice.
Washington car seat checker
4′9″ = 57 in. Enter only the boxes you have. Washington uses exit at 4′9″ only; age is not a trigger, so a child under 4′9″ still needs a booster regardless of age.
Heads up: Washington’s current rules took effect January 1, 2020 (SB 5407): rear-facing to 2, harness to 4, booster to 4′9″, rear seat under 13. Older "age 6 / 60 lb" descriptions are pre-2020 and outdated.
- Child
- Not entered
- Minimum legal stage
- Enter age / height / weight
- Booster-exit rule
- exit at 4′9″ only; age is not a trigger, so a child under 4′9″ still needs a booster regardless of age
- First-offense fine
- No set statutory amount
Plain-language summary, not legal advice.
This shows the minimum legal requirement in Washington, not best safety practice, which is usually stricter, and not legal or safety advice. Always follow your car seat's manufacturer instructions. For the full four-stage rules, front-seat rule, and citation, see the Washington car seat law reference, cited to RCW 46.61.687 (last reviewed 2026-07-09).
How Washington car seat law works
Washington rewrote its child-passenger law effective January 1, 2020 (SB 5407), and any summary describing "age 6 or 60 lb" is quoting the old, repealed version. The current law legislates rear-facing under 2, a harness under 4, and, distinctively, a booster until the child reaches 4′9″. Washington is the only state whose booster exit is height-only: age is not a trigger, so a 10-year-old under 4′9″ still legally needs a booster, and the statute itself notes this is usually ages 8–12. Front-seat placement is real law here (under 13 in the rear "where practical"), unlike the states that only recommend it. One honesty note: RCW 46.61.687 does not set a dollar fine. The ~$136 figure comes from the court penalty schedule, not the statute.
This checker shows the Washington minimum legal requirement (not best safety practice, which is usually stricter) and is not legal or safety advice. For the full four-stage rules, front-seat rule, and citation, see the Washington car seat law reference.
Car seat checkers for other states
Same tool, each with its own booster-exit rule.