The normal size sink is 33 inches. For the sink to be set up, you'll have to have sufficient space for clips to be set up to maintain the sink into the countertop. Although installation requirements differ from sink to sink, generally you'll have to have approximately 1/2 inch to an inch space on the faces of the sink so as to install it properly.
Undermount sinks will be set up beneath the countertop and sealed into the countertop with silicone sealant and then reinforced with clips to the bottom of the countertop. These clips will require a little quantity of distance to be set up. By way of instance, a normal sink foundation that's 33 inches wide may match a 32 1/2" sink or even smaller. If you want to install 27 inch undermount basin in your kitchen, then you can search the web.
Be certain that if you examine measurements of a sink, consider the general dimensions; in different words, the dimensions from one edge of the sink to another, and not simply the size of the bowls. In case you've got a 33-inch sink base cabinet, anything bigger than a 32 1/2 inch sink won't fit without some type of custom cupboard.
These sinks may have ridges under so that clips can be set up easily to seal the sink place.