Tools · Car Seat
Wisconsin Car Seat & Booster Checker (2026)
Enter your child's age, height, and weight to see the minimum seat stage Wisconsin law requires and the first-offense fine ($30–$75 first offense). This is the legal minimum — not best safety practice.
Wisconsin car seat checker
4′9″ = 57 in. Enter only the boxes you have. Wisconsin uses a child aged 4–7 needs a booster while under 80 lb AND under 4′9″; reaching age 8, 80 lb, or 4′9″ exits.
- Child
- Not entered
- Minimum legal stage
- Enter age / height / weight
- Booster-exit rule
- a child aged 4–7 needs a booster while under 80 lb AND under 4′9″; reaching age 8, 80 lb, or 4′9″ exits
- First-offense fine
- $30–$75 first offense
Plain-language summary, not legal advice.
This shows the minimum legal requirement in Wisconsin, 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 Wisconsin car seat law reference, cited to Wis. Stat. §347.48(4) (last reviewed 2026-07-11).
How Wisconsin car seat law works
Wisconsin legislates the whole ladder by age and size, which makes it unusually clear. A child under 1 year old and under 20 lb must ride rear-facing in a back seat, so rear-facing is real law here, not just an AAP recommendation. From age 1 to under 4 (and 20 lb up) the child rides in a forward-facing harness, and from age 4 to under 8 a booster is required while the child is under 80 lb and under 4′9″. The booster exit uses three factors at once: reaching age 8, 80 lb, or 4′9″ ends it. One honest note on money: the base statutory forfeiture is $30–$75 for a first offense, and the larger figures you see quoted (near $150) are county court totals with surcharges added, not the statute amount.
This checker shows the Wisconsin 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 Wisconsin car seat law reference.
Car seat checkers for other states
Same tool, each with its own booster-exit rule.