What You Need

  • New toilet seat (measure your toilet bowl first — standard Australian sizes are round or elongated; most modern Australian toilets are elongated/D-shaped)
  • Flathead screwdriver
  • Adjustable spanner or pliers (may not be needed if plastic wing nuts)
  • Gloves (recommended)

Step-by-Step

  1. 1

    Locate and open the hinge bolt covers

    At the back of the toilet, where the seat attaches to the bowl, you will see two plastic hinge points. Each usually has a cap that snaps or slides to reveal the bolt underneath. Pry up or slide these caps with a flathead screwdriver.

  2. 2

    Unscrew the bolts

    With the caps open, you can see the bolt from above (in the hinge) and the nut below the toilet bowl rim. Hold the bolt still from the top with a screwdriver if needed, while unscrewing the nut underneath with a spanner or by hand if it is a plastic wing nut. Remove both bolts completely.

  3. 3

    Lift off the old seat and clean the mounting area

    Lift the old seat and lid assembly straight up and off. Clean the hinge mounting holes and the top of the toilet bowl at the hinge points — mineral deposits and grime often accumulate here. A bathroom cleaner and old toothbrush work well.

  4. 4

    Position the new seat and secure the bolts

    Set the new seat on the bowl, aligning the bolt holes with the mounting holes. Drop the bolts through from above. Hand-tighten the nuts underneath first, checking the seat is centred and sitting squarely. Then tighten firmly with the spanner — snug but not so tight that you crack the porcelain or the plastic seat. Snap the bolt caps closed.

  5. 5

    Test and adjust

    Open and close the seat and lid to check they operate smoothly and the seat sits level. Most seats have slight adjustability in the hinge position — loosen the bolts slightly, reposition and retighten if the seat is not sitting evenly.

Choosing a replacement seatMeasure the length and width of your toilet bowl before buying. Australian standard sizes: elongated/D-shape (most common, approximately 47cm long) or round (less common, approximately 42cm). Soft-close seats (the hinge slows the seat as it closes) are more expensive ($50–150) but significantly more durable and less noisy than standard hinges. They are worth the upgrade.

Frequently Asked Questions

Apply penetrating oil (WD-40) to the nut from below and leave for 30 minutes. Try again. If still stuck, use a hacksaw or oscillating tool to cut through the bolt between the nut and the toilet bowl. Be very careful not to scratch the porcelain. Once the old seat is removed, the bolt stub remaining can be pushed out from below. Replacement bolt kits are available at hardware stores.
No — seats are not universal. Measure your bowl: the length from the front of the bowl to the centre of the bolt holes, and the width at the widest point. Also check the bolt hole spacing (usually 150mm centre-to-centre for Australian toilets but varies). Bring these measurements to the hardware store. Most toilet seat packaging lists compatible bowl shapes and dimensions. When in doubt, bring a photo of your toilet.