You may be wondering, do bathroom sinks come in a standard size? Truth is, no, there are no rules. For instance, some sinks are so petite that your hands just fit while others are large enough for a quick wash of the hair. Based on common Australian bathroom sink dimensions, round sinks are 300mm - 400mm in diameter, while rectangular sinks are 400mm - 550mm in length and 300mm – 400mm wide.
The typical internal depth is 100mm - 150mm, and the overall bathroom sink height (from the floor to the rim of the sink) ranges between 750mm – 900mm, depending on your vanity and height needs.
When searching for a new sink, the last thing you want to do is measure it incorrectly – and then order the wrong one! That’s why it’s imperative to know the correct measurements. For square or rectangle sinks, measure the outer length, width and depth. For round or oval sinks, measure the length across the widest point of the sink. If installing an undermount or inset/drop-in sink, ensure there is clearance within your vanity for the sink height.
Also, it’s important to consider any available wall and/or benchtop space and note where the plumbing is. Keep in mind that if the existing vanity remains, then the new sink must match those specifications. Otherwise, the cut-out opening will need to be resized (resulting in more labour and costs). If the old vanity is being replaced, then choosing the right size sink comes down to personal preference, space and practical usage.