best booster seat for 4 year old australia

The “best” booster for a 4‑year‑old in Australia is usually not a booster at all—keep them in a forward-facing harnessed seat (Type G) meeting AS/NZS 1754 as long as they fit the height markers. If they’ve outgrown that, choose a high-back booster that gives a lap–sash fit with the lap belt low on the hips, shoulder belt mid-shoulder, and good head support. Look for adjustable headrest, deep side wings, anti-submarining design, and belt guides that don’t fight you; some models have lower attachments to steady the seat, but the car’s belt restrains the child. Do a test fit in your car and with your kid—no slumping, knees bend at the edge, and zero “I’m sliding out like a penguin” vibes. Expect new prices around AUD $120–$450; avoid second-hand seats with unknown history or past crashes, and check the expiry on the sticker. It’s not glamorous, but getting the fit right beats any fancy cup holder.