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 Older "age 6 / 60 lb" descriptions are pre-2020 and outdated.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law effective January 1, 2020 (SB 5407), and any summary describing "age 6 or 60 lb" is quoting the old, repealed version.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.