Replacing 2019 RP190 Kitchen Sink

I replaced the plastic sink (top mount) that came with the 2016 RP179 with a larger bar type sink. I did have to enlarge the opening carefully. Since it had a large rim with holes for the faucet, that is where it went. Just remember that if you do go to a top-mount sink and have to enlarge the opening to measure two or three times before cutting. Making a template that fits the sink and then using that to mark the opening helps also. And, it is better to cut tight and then have to cut a bit more than to cut the opening too large. It is much easier to enlarge an opening than to shrink one. 

Many sinks come with a paper template for cutting the hole in the counter top.  Surface mount sinks often come with a u-shaped bracket spot welded to the underside of the surface mounting flange that has to be accounted for since it has to be just inside the hole around the edges for the screws and mounting clips to fit.  If the sink you're mounting has the mounting u bracket and there is no template, then you can measure from the outside edge of the sink to the bracket to mark the edges of the hole.  I agree with StephenH, that its best to err on the side of being conservative in cutting, since you can always make it bigger, but can't make it smaller.  Good luck!