how tall to be out of car seat

In Australia there isn’t one magic height to ditch the booster; the law is based on age groups, and then proper belt fit.

Most kids need a booster until the adult seat belt fits correctly—often around 145 cm and roughly 10–12 years, but cars and kids vary.

Use the five‑step test: sit back against the seat, knees bend at the edge, sash belt sits mid‑shoulder, lap belt low over the hips, and they can stay like that the whole trip.

If any of that fails, keep the booster; it’s cheaper than physiotherapy and far safer.